EP0014345B1 - Closing device for the discharge opening in the bottom of a container - Google Patents

Abstract

An apparatus for closing a discharge opening (3) in the bottom (1) of a container, preferably a rotary mixing table of a processing machine, comprising a closure cover (4) which is arranged on a rotary shaft (5) through a support arm (6). The rotary shaft (5) and the support arm (6) are provided outside the container and adjacent the bottom thereof. A resilient means (8) is disposed between the closure cover (4) and the support arm (6) which are connected together by way of a hinge (7). Preferably the resilient means can be a rubber or plastic member which is faced with metal members (16, 19) and which is arranged between the closure cover (4) and a pivot bearing (9). The pivot bearing (9) is secured to the support arm (6) and has a bearing plate (11) with screw threaded bores (13, 14) for mounting at least one pressure screw (15) and an adjusting screw (17).

Description

The invention relates to a device for closing an emptying opening arranged in the bottom of a container, preferably a turntable of a processing machine, with a closure lid arranged on a rotary shaft via a support arm and entering the emptying opening, the rotary shaft and support arm being provided outside the container next to the bottom thereof.

Sealing devices of the type mentioned above, in particular for mixing machines with a rotating plate, are known in principle. However, the closure cover is always rigidly connected to the support arm and the rotary shaft. In such an arrangement, the closure cover then necessarily executes a circular movement around the rotary shaft. In this construction, it is disadvantageous that the closure lid can only be retracted into the emptying opening of the container bottom if there is considerable play between the outside diameter of the closure lid and the inside diameter of the emptying opening, so that the horizontal movement component of the circular movement is caused by the difference in diameter resulting gap can be intercepted. Due to the gap there is, however, considerable leakage in this embodiment, so that no liquid or fine-grained substances can be treated in such a sealed container.

Attempts have already been made to counteract this difficulty by providing a flat rubber sealing ring on the underside of the closure cover, which covers the gap downwards and outside the container. Although this version is already an improvement over the first known construction, there is still the problem that (still unmixed) material settles in the gap that is still present and that when processing coarse-grained material (e.g. . Concrete chips) jamming can occur. The seal is also insufficient for the processing of liquid material, because the rubber seal only lies on the outside against the bottom of the container bottom and cannot be pulled into a tight seal seat due to the horizontal movement components.

Another disadvantage is that with a thicker container bottom, the vertical movement component is correspondingly larger than with a thinner container bottom, so that the gap width that then results is no longer acceptable for proper operation. On the other hand, however, there is a need in some applications to make the tank bottom thicker for structural reasons, in particular in the case of larger mixing machines, or to line it with additional wear plates or other coverings, such as, for. B. tiles made of melted basalt, cast tiles, etc. In addition, a sufficiently large sealing surface should be available on the lower edge of the emptying opening. Container bottoms with the thickness described above cannot be closed or cannot be closed sufficiently with the known devices described, which are also referred to as flap closures.

A flap closure on mixing machines is also known, in which the circular movement during entry into the container bottom is converted into a linear movement by parallel guidance. This construction is disadvantageous in terms of machine technology, requires a large overall height of the mixing machine and requires extensive maintenance and care work, especially since this mechanism with its pivot bearings moves in a space through which the material flowing out of the mixing container flows.

Furthermore, an elaborate swivel lock was developed to overcome the problems of the known flap lock. In this, the support arm pivots the closure lid by a vertical, i.e. H. vertical wave from an area outside directly under the drain opening in the bottom of the container. Then a vertical lifting movement for moving the closure lid into the emptying opening is triggered. Although these swivel locks work satisfactorily in terms of function, the costs and the maintenance effort are unacceptably high. Due to the necessary vertical and additional horizontal movements, either two drive systems must be available or a complicated lever system ensures the conversion of the horizontal movement component into the vertical movement component. In addition, such swivel locks below the mixing machine disadvantageously require considerable space for executing the swiveling movement. This must be so large that the closure lid can be pivoted completely out of the area of the emptying opening.

The object of the invention is therefore to provide a closing device of the type mentioned, with which despite reliable construction and favorable installation conditions, a reliable closure with considerably better tightness is provided.

This object is achieved in that the closure lid and the support arm, between which an elastic member is connected, are rigidly connected to one another via a hinge having tabs and rotatably connected to one another about a tilt axis, and in that the tilt axis is formed by a tilt bearing arranged in the tabs . As a result, a flexible arrangement of the closure cover on the support arm is created for the first time in the relevant technical field without the robust structure and the maintenance-free reliable function being damaged. Advantageously, the first part of the closing movement is still carried out by means of a normal circular movement, in which the support arm moves on an arc through the driven rotary shaft. However, as soon as the closure cap reaches the centering ring of the discharge opening at the bottom of the container and abuts there, the elastic member engages, allowing the closure cover to be deflected from the circular movement, so that it slides perpendicularly to the closure cover into the discharge opening, while the support arm holding the cover the circular movement ends. The elastic member thus compensates for the difference in the direction of movement between the centering ring or the inner edge of the emptying opening on the one hand and the outer edge of the closure cover on the other. The structure of the rigid support arm, which is fixed to the rotary shaft and is known from the prior art, can be maintained because the elastic member is seen in function only behind the support arm, ie between the latter and the closure cover.

In an advantageous further embodiment of the invention, the elastic member is a rubber or plastic part covered with metal plates, which is arranged between the closure cover and the tilting bearing, the tilting axis of which runs parallel to the axis of the rotary shaft and which has a radial spherical plain bearing. Such an elastic member is sometimes referred to as "vibrating metal" and has the shape of a cube or cuboid, which has a compressible elastic plastic or rubber body inside, which is reinforced on at least two opposite surfaces with the metal plates mentioned, for. B. with a laminated core or a thicker iron sheet. The metal reinforcement on the two outer sides results in good mechanical engagement options which are also used according to the invention in this elastic member.

The tilt bearing allows movement of one metal plate of the elastic member with respect to the other, although of course both plates are firmly connected to each other with the exception of the described tilting possibility, e.g. B. on landings, as will be described. A spring or a hydraulic or pneumatic bellows could also be used as the elastic link.

Due to the elastic member arranged on the tilting bearing, the closure cover is practically connected to the support arm via a hinge which, as mentioned above, allows the tilting movement in the required direction. Preferably and in order to simplify the bearing parts on the tilting bearing, tilting in only one direction is permitted.

It is also advantageous according to the invention if the tilting bearing is fastened to the support arm and has a bearing plate with threaded bores for receiving at least one pressure screw and one adjusting screw. Said bearing plate connects the two radial spherical bearings and is in the form of at least one web or a plate on the side of the closure cover which is opposite in relation to the elastic member. As a result, the pressure and adjusting screws can exert their full effect on the elastic member on the one hand and the closure cover on the other.

Possibly required tensile forces when opening, d. H. when pulling the closure lid out of the emptying opening, are transferred via the tilting bearing, the bearing plate and the bearing webs, namely from the closure lid - except for the tilting option described above - rigidly to the support arm. This gives you all the advantages of the sturdy, rigid mounting of the known flap closures and nevertheless achieves a good sealing possibility with the measures according to the invention, because the gap can be made considerably smaller than the two known solutions due to the difference between the outside diameter of the closure cover and the inside diameter of the emptying opening.

According to the invention it is provided in a useful further embodiment that the pressure screw is pressed against the side of the elastic member facing away from the sealing cap, which has a blind hole for the passage of the adjusting screw on the metal plate attached to the sealing cap or a pressure plate of the elastic member is held down. With the pressure screw, the prestressing on the elastic member can thus be set in a very simple manner. For example, pressing the pressure screw down compresses the elastic body arranged between the metal plates, so that the elastic member acts harder. The opposite is of course achieved when the pressure screw is unscrewed.

Use the adjusting screw to adjust the cover, especially at the beginning of the vertical movement. Such an adjustment is useful so that the closure lid is parallel to the bottom of the container in the closed state.

Furthermore, stop screws can also be provided, or the adjusting screws can take over their function, namely. Determine end positions of the elastic member so that occurring pressures, for. B. with material jams during the closing process, do not overload the elastic member.

It is also expedient according to the invention if the closure cover in the middle region is held in a rotary bearing Pivot and has a sealing ring on the outside. The arrangement of the sealing ring means that the annular gap, which can be adjusted extremely narrowly by the measures according to the invention, can even be sealed in a liquid-tight manner, by means of the pivot bearing and the pivot even for a rotating cover. This closing device is therefore also of particular interest for compulsory mixers with a rotating container.

• Fig. 1 abgebrochen und teilweise im Schnitt die Verschließvorrichtung, wobei der Verschlußdeckel in der Entleerungsöffnung angedrückt gehalten ist,
• Fig. 2 eine ähnliche Ansicht wie in Fig. 1, wobei jedoch mit ausgezogenen Linien nach dem Herausziehen des Verschlußdeckels aus der Entleerungsöffnung der Zustand zu Beginn der Kreisbewegung und mit strichpunktierten Linien nach Drehung der geöffnete Zustand gezeigt sind, und
• Fig. 3 eine teilweise abgebrochene Einzelansicht entsprechend der Linie 111-111 in Fig. 2.

Further advantages, features and possible applications of the present invention result from the following description in conjunction with the drawings. It shows

• 1 broken and partially in section the closing device, the closure lid being held pressed in the emptying opening,
• Fig. 2 is a similar view as in Fig. 1, but with solid lines after pulling the cap out of the emptying opening, the state at the beginning of the circular movement and with dash-dotted lines after rotation, the open state are shown, and
• FIG. 3 shows a partially broken off individual view along line 111-111 in FIG. 2.

The tank bottom 1 shown in FIGS. 1 and 2 is covered with armor 2 on its surface. This results in a not inconsiderable material thickness in the emptying opening 3, so that the closure cover 4, the surface of which must be flush with the surface of the armor 2 of the container base 1, must perform a not inconsiderable component of movement transversely to the container base 1, after which the circular movement described above occurs along the arc lines shown in Fig. 2.

The embodiment shown here is a compulsory mixer, the turntable axis of which is not perpendicular but an angle of z. B. is tilted 30 ° from the vertical. Therefore, the container bottom 1 is shown obliquely in FIGS. 1 and 2. The container designed as a turntable extends upwards, so that the arrangement shown here is outside the container and below it.

On the driven on the machine frame, not shown, and rotatably mounted rotary shaft 5, the support arm 6 is attached, which carries the closure cover 4 at its free end via the hinge 7 (Fig. 3), the elastic member 8 and the tilt bearing 9.

With the exception of the tilting movement about the tilt axis 10 (FIGS. 2 and 2), the closure cover 4 and the support arm 6 are rigidly connected to the tilt bearing 9 via the hinge 7. The tilting is made possible in that the tilting bearing 9 has spherical bearings 12 on the outside at the opposite ends of a bearing plate, which are only shown in FIG. 3. It can thus be seen that, according to FIG. 3, the closure cover 4 cannot be tilted in the paper plane, but can be tilted perpendicular to it, namely about the tilt axis 10, which lies parallel to the axis of the rotary shaft 5.

1 shows the operating position, in which the tilting bearing 9 is tilted while compressing the left half of the rubber or plastic part. 2 shows the relieved state.

The bearing plate 11 of the tilt bearing 9 has threaded holes 13 and 14, which can only be seen in the sectional views of FIGS. 1 and 2, the pressure screw 15 against the outer metal plate 16 and the adjusting screw 17 (both secured by lock nuts 18) against the inner metal plate 19 of the elastic member 8 is screwed, held pressed and thereby pressed against the pressure plate 24. It can also be seen that the middle rubber part of the elastic member 8 has a bore 20 which is extended to be flush with the bore 21 of the outer metal plate 16 for receiving the adjusting screw 17. This results in a blind bore 20, 21 in the elastic member 8.

At the left end in FIGS. 1 and 2, a strip 22 is screwed to the bearing plate 11 of the tilting bearing 9 for holding and guiding the elastic member 8. The rubber ring 26 fastened by means of the pressure ring 23 on the outer circumference of the closure cover 4 can be clearly seen from FIG. 3.

Not shown is the structural design of a closure cover, which is forcibly preferably driven at a variable speed. The drive is attached to the cover so that it follows the deflection movement.

In operation, after installing the closing device, the prestressing of the elastic member 8 is first set by tightening the pressure screw 15. Then, by screwing in the adjusting screw 17, such a position of the closure cover 4 is adjusted that when the position shown in solid lines in FIG. H. during the transition from the linear to the rotary movement, the free outer end of the adjusting screw 17 just lies against the inner metal plate 19, as shown in FIG. 2. This ensures that the surface of the cap 4 is really parallel to the surface of the bottom 1 of the container. With 25, the bearing bush for the cover 4 is designated.

From the position shown in dash-dotted lines in FIG. 2, after actuation of the drive, not shown, by rotating the rotary shaft 5, the support arm 6 is moved along the arcs to the position shown in solid lines in FIG. 2. On the side facing the rotary shaft 5, the closure cap 4 abuts against the inner edge of the emptying opening 3, and now the translational movement begins in the direction of the axis of rotation of the turntable, the base 1 of which is shown. Here the aesthetic limb 8 is compressed on the left and slightly stretched on the right (as shown). This takes place when the closure cover 4 is pushed in until the position shown in FIG. 1 is reached.

Claims (5)

1. Apparatus for closing a discharge opening (3) which is disposed in the bottom (1) of a container, preferably a rotary table arrangement of a processing machine, having a closure cover (4) which is disposed on a rotary shaft (5) by way of a support arm (6) and which moves into the discharge opening (3), wherein the rotary shaft (5) and the support arm (6) are disposed outside the container and beside the bottom (1) thereof, characterised in that the closure cover (4) and the support arm (6) between which a resilient member (8) is interposed are rigidly connected together rotatably relative to each other about a tilt axis (10) by way of a hinge (7) having side plate members, and that the tilt axis (10) is formed by a tilt bearing arranged in the side plate members.

2. Apparatus according to claim 1 characterised in that the resilient member (8) is a rubber or plastics member which is fitted with metal plates (16, 19) and which is arranged between the closure cover (4) and the tilt bearing (9), the tilt bearing having its tilt axis (10) extending parallel to the axis of the rotary shaft (5) and having a radialballsocket bearing.

3. Apparatus according to claim 1 or claim 2 characterised in that the tilt bearing (9) is secured to the support arm (6) and has a mounting plate (11) with screwthreaded bores (13, 14) for receiving at least one pressure screw (15) and adjusting screw (17).

4. Apparatus according to one of claims 1 to 3 characterised in that the pressure screw (15) is held pressed against the side of the resilient member (8), which is remote from the closure cover (4), the resilient member (8) having a blind bore (20, 21) for receiving the adjusting screw (17) which is held pressed against the metal plate (19) secured to the closure cover (4) or a pressure plate (24) of the resilient member (8).

5. Apparatus according to one of claims 1 to 4 characterised in that the closure cover (4) has in the middle region a rotary trunnion member mounted in a rotary bearing, and a sealing ring (26) on the outside.

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