GB2040024A

GB2040024A - Closure valve for the outlet aperture of a container for loose material

Info

Publication number: GB2040024A
Application number: GB8002338A
Authority: GB
Original assignee: RICHTER ROHRLEITUNG
Current assignee: RICHTER ROHRLEITUNG
Priority date: 1979-01-23
Filing date: 1980-01-23
Publication date: 1980-08-20
Also published as: FR2447336B1; FR2447336A1; BE881285A; DE2902430C2; NL8000422A; DE2902430A1; GB2040024B

Abstract

The valve plate (7) is movable along sliding guide rollers (8) within a housing (6) and can be urged vertically against a gasket (4) running around the outlet aperture (A) by means of a cam means (14), which extends substantially over the entire length of the front and/or back edges of the outlet aperture (A). A rod (10) moves the plate between open and closed positions, while a rod (16) through links (15) rotates the cam means. <IMAGE>

Description

SPECIFICATION Closure valve for the outlet aperture of a container The present invention relates to closure valve for the outlet aperture of a container for loose material, the valve including a valve plate, which is slidable within a housing along a guide, and which can be urged against a gasket running around the outlet aperture by means of a cam device adjacent to the valve plate in the area of the periphery of the outlet aperture.

A valve of this kind is described in German Patent No. 932 599, where the cam device consists of a single locking cam, arranged centrally below the valve plate, with eccentric pivotal mounting on a sliding support, which can be moved horizontally on tracks.

A connecting rod leading outside, which also forms the axis of rotation of the locking cam, serves not only for the actuation of the locking cam, but also for the movement along the sliding guide of the unit consisting of a sliding support, the valve plate and the locking cam. The mounting and control of the valve plate are not reliable in operation on the sliding support because of flexible connections, both during the movement of the sliding support carrying the valve plate, and during the actuation of the locking cam. In addition to this tilting of the valve plate during the pressure against the outlet orifice cannot reliably be prevented, and the single locking cam does not guarantee a completely tight position of the valve plate against the gasket.The valve plate cannot stop in an intermediate position to decrease the size of the opening of the outlet aperture, because falling loose material would damage the flexible mounting of the valve plate on the sliding support, and raising and pressing of the valve plate can only be effected when the valve plate is in its final position below the outlet aperture. The tracks for the sliding support can quickly become obstructed with falling material and inhibit the sliding movement.

Another slide for closing the outlet aperture of a container for loose materials is described in German Auslegeschrift No. 1,781,411. In this case, too, the valve plate is brought into the closed position by means of a cam device. A horizontal row of single eccentric cams actuated by means of a hand lever, is mounted in a rotatable manner on each of the opposite sides below the outlet aperture, the upper surfaces of which eccentric cams, when they are in the lowered position, form the sliding guide for the valve plate; in their raised position the eccentric cams press the valve plate against the gasket. In this case, two rows of single cams are provided, which effect a more even disposition of the valve plate against the outlet aperture than a single eccentric cam acting upon the centre of the plate.However, by his method as well, only pointwise support of the valve plate is obtained in the closing position, and thus there is a danger of leaks if the valve plate distorts. The operation of this valve is complicated, because the eccentric cams of each row must be actuated individually by means of hand levers. In addition to this, individual actuation can mean that particular eccentric cams are not brought into their final closed position, so thalthe pressure effect on the valve plate is uneven. A further disadvantage with this arrangement is that the eccentric cams form the sliding guide for the valve plate, which subjects them to a higher degree of wear, and wears away their cam surfaces prematurely, so that the force of their pressure is reduced.This problem must be prevented by making the valve plate thin and light, and only using it with light loose material. In view of the manual operation of the single eccentric cams, it is also important to have as little weight as possible bearing on the eccentric cams. Thus the known valve can only be used with small containers and prescribed loose materials, and its range of application is limited.

Afurthervalve is known, in accordance with German Offenlegungsschrift No. 2,650,677, where the valve plate is fixed onto a movable frame by means of cover plates. Immediately prior to the abutment of the valve plate against a stop plate at the end of the entry movement, the cover plates rise up from their sloping normal position and lift the valve plate into the closed position. With this valve, several moving parts work together, the mobility of which can be impaired by falling material, which disrupts the sliding motion. The expensive construction is made even more expensive by the fact that the components must be very strong so that they do not distort when the valve plate exerts high pressure against the support.Whether a completely tight arrangement of the valve plate around the sealing rims of the outlet orifice can be achieved by this device is doubtful, because the valve plate is only support pointwise on the cover plates, and play induced by the wear of the moving parts cannot be compensated for by this support.

According to the present invention there is provided a closure valve for the outlet aperture of a container for loose material, which closure valve comprises: a housing extending around the outlet aperture of the container, the housing incorporating a gakset which extends around said outlet aperture; a valve plate which is slidable within a guide provided in the housing; and a cam device mounted in the housing adjacent to a peripheral edge of the outlet aperture, the cam device being located on that side of the valve plate opposite to the gasket, the cam of the cam device extending adjacent to the valve plate over substantally the entire length of the associated peripheral edge of the outlet aperture.

Thus the valve plate is pressed against the gasket of the housing in a continuous uninterrupted line substantially over the length of the associated peripheral area of the outlet aperture, so that a gasand water-tight seal is produced at the outlet aperture. A single actuator suffices for the movement of the cam which is of a length suitable to the outlet aperture. The construction is simple and robust, and because of the small number of movable parts, it will work over a long period practically maintenance-free. The long cam not only clamps the valve plate tightly in the final closed position, but permits the adjustment of any gap width of the outlet aperture. In this way, the locking mechanism is so firm that unintentional displacement of the valve plate by the pressure of the loose material cannot occur.The dimensions and form of the valve plate are immaterial to the function of the cam devie, because the cam is adapted to these dimensions, and is able to support both long and short sides of the valve plate evenly. The sliding guide for the valve plate is independent of the cam device and only comes into action when the valve plate is released and affords free movement of the valve plate for opening or closing the outlet aperture. Thus neither the sliding guide nor the valve plate is subject to much wear.

Advantageously, the sliding guide consists of a substantially horizontal row of rollers is arranged on each of the opposite sides of the housing, upon which rollers the lower surface of the valve plate is slidable. The two roller paths afford an easy, quiet and wear-free backwards and forwards motion of the valve plate. The cam of the cam device and the rollers form the only movable parts of the valve, and can be mounted in the housing so that they will neither jam nor be obstructed by falling material.

Preferably, the cam is formed on a shaft, the ends of which shaft are mounted in opposite walls of the housing, which shaft is rotatable to a limited extent by means of an operating rod. The operating rod may comprise a substantially horizontal rod located externally of the outlet aperture and which engages the cam shaft which is transverse to the horizontal rod by way of a rotatable linking plate. The horizontal rod may be arranged inside or outside the housing, and can be straight or bent.

The operating rod may be movable manually or by means of a working cylinder. This is dependent upon the weight of the valve plate and the size of the outlet aperture of the container to be closed. Correspondingly, the valve plate may be movable on the rollers by hand or by means of a centrally operating working cylinder. The valve plate may consist of a simple piece of sheet metal. It is unnecessary to manufacture a special valve. The housing may consist of weak sheet metal, because it is stabilised by the cam shaft, and because it does not have to bear pointwise or uneven pressures, but is loaded evenly over its area.

In the case of a small valve, one cam is sufficient to achieve satisfactory sealing of the valve. It is advantageous that the cam shaft is arranged - seen from the direction of the movement of the valve plate outside the front or back edge of the outlet aperture.

The rows of rollers are situated transverse to the cam shaft on the sides of the housing, also outside the outlet aperture. In this way the only moving parts of the valve are situated on the other side of the outlet aperture and cannot be affected by falling material, which means that the valve operates over long periods of time practically maintenance-free, regardless of whether the container is filled with fine or coarse, or more or less moist loose material.

With large valves it is expedient to arrange a cam shaft - seen from the direction of movement of the valve plate - outside both the front and back edges of the outlet aperture. It is advantageous that both cam shafts are moved simultaneously by means of a common operating rod. Thus the cam shafts work in complete synchrony and an even pressure of the valve plate against the gasket running round the outlet aperture is achieved. In this case the rows of rollers are situated between the two cam shafts.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows a side view of a closure valve according to the present invention; Figure 2 shows a top view of the valve shown in Figure 1; Figure 3 is a section along the line Ill-Ill in Figure 2, to illustrate the valve in the open position; Figure 4 is a section along the line IV-IV in Figure 5, but illustrating the valve in the position shown in Figure 3; Figure 5 is a section along the line V-V in Figure 2, to illustrate the valve in the closed position; and Figure 6 is a section along theline VI-VI in Figure 3, but illustrating the valve in the position shown in Figure 5.

The valve shown in the figures comprises a housing 1, which can be attached by means of a flange 2 to the base of a container (not shown) and which protrudes laterally from the outlet aperture of the container. A connecting piece 3 of the housing, connected to the flange 2, continues the square outlet aperture symbolised by an arrow A. On its lower edge, the connecting piece 3 carries a gasket 4 running around the aperture, which gasket protrudes somewhat below a support 5.

Sidewalls 6 of the housing 1, inclined at their lower ends, define a discharge shaft in which there is situated a valve plate 7. The valve plate 7 can consist of a simple piece of sheet metal of any strength.

Situated in the sidewalls 6 of the housing are parallel rows of freely rotatable rollers 8 on support bolts 9. The rollers can consist of grooved ball bearings. According to Figures 3 and 4, the valve plate 7 lies with its lower surface on the rollers 8, and can be moved freely backwards and forwards on the rollers. With small valve plates the movement can be effected by hand. With large valve plates 7, it is more practical to use a centrally operating working cylinder 10 for example a pneumatic cylinder, for movement of the valve plate.

Two shafts 11 and 12 serve for lifting the valve plate 7 from the rollers 8 into any position below the outlet aperture A, the ends of which shafts are rotatably mounted in the sidewalls 6 of the housing by means of bearings 13. On each of the shafts there is formed an eccentric body 14 which extends substantially along the entire length of the associated peripheral area of the outlet aperture. The two eccentric shafts 11 and 12 are arranged - seen from the direction of movement of valve plate 7 - outside the front and back edges of the outlet aperture. Two downwardly extending rotatable plates 15 are welded onto the lower surface of each of the shafts, and a rod 16 is movably mounted between the plates 15 by means of bolts 17. The rod 16 can be produced from a sheet-metal strip which is reinforced at 18.

The rod can be straight or curved, depending on the requirements of the situation. A boss 19 of the rod 16 is acted upon by a pneumatic cylinder 20, the movement of which, via the rod 16, effects s simultaneous horizontal swivelling of the two eccen tricshafts 11 and 12. If necessary this movement can be carried out by hand.

In order to permit movement of the valve plate 7 for opening or closing the outlet aperture, the two eccentric shafts 11 and 12 are rotated by means of the rod 16 to the position shown in Figure 3, so that they are released from the valve plate, and the valve plate lies on the rollers 8, and can be pushed backwards and forwards as desired.

In order to lock the valve plate 7 into its position, or into any intermediate position between the open and closed positions, the two eccentric shafts 11 and 12 are turned by the pneumatic cylinder according to Figures 5 and 6, so that the two long eccentric bodies of the eccentric shafts 11 and 12 press evenly against the lower surface of the valve plate 7 and the upper surface of the valve plate presses against the gasket 4. Since the valve plate is supported evenly over the entire length of at least one long edge, a gas- and water-tight sealing of the outlet aperture or, if the valve plate is set in an intermediate position (Figure 2), an efficient locking is produced, which reliably prevents an unintentional movement of the valve plate resulting from the pressure of the loose material or from the pneumatic cylinder 10.

Thus, the illustrated embodiment of the present invention provides a closure valve with a cam device such that the valve plate is lockable in any position relative to the outlet aperture, and is urged in any position quite evenly, and without tilting, against the sealing rims of the housing, regardless of the weight or variety of the material bearing on the valve plate, and such that the cam device can be actuated centrally. A simple construction is obtained with only a few moving parts, permitting virtually maintenance-free operation of the valve.

Claims

1. A closure valve for the outlet aperture of a container for loose material, which closure valve comprises: a housing extending around the outlet aperture of the container, the housing incorporating a gasket which extends around said outlet aperture; a valve plate which is slidable within a guide provided in the housing; and a cam device mounted in the housing adjacent to a peripheral edge of the outlet aperture, the cam device being located on that side of the valve plate opposite to the gasket, the cam of the cam device extending adjacent to the valve plate over substantially the entire length of the associated peripheral edge of the outlet aperture.

2. A valve as claimed in claim 1, wherein a substantially horizontal row of rollers is arranged on each of the opposite sides of the housing, upon which rollers the lower surface of the valve plate is slidable.

3. A valve as claimed in claim 1 or 2, wherein the cam is formed on a shaft, the ends of which shaft are mounted in opposite walls of the housing, which shaft is rotatable to a limited extent by means of an operating rod.

4. A valve as claimed in claim 3, wherein the operating rod comprises a substantially horizontal rod located externally of the outlet aperture and which engages the cam shaft which is transverse to the horizontal rod, by way of a rotatable linking plate.

5. A valve as claimed in claim 4, wherein the horizontal rod is arranged inside or outside the housing and is either straight or curved.

6. Avalve as claimed in claim 3,4 or 5, wherein the operating rod is movable manually.

7. A valve as claimed in claim 3,4 or 5, wherein the operating rod is movable by means of a working cylinder.

8. Avalve as claimed in any preceding claim, wherein a cam is arranged, seen from the direction of movement of the valve plate, adjacent to the front and/or the back edge of the outlet aperture.

9. A valve as claimed in claim 8, when appendent to any one of claims 3 to 7, wherein with two cam shafts both shafts are simultaneously movable by means of a common operating rod.

10. A valve as claimed in any preceding claim, wherein the valve plate can be moved along the rollers by means of a centrally-operating working cylinder.

11. A valve as claimed in any one of claims 1 to 9, wherein the valve plate can be moved along the rollers by hand.

12. A valve as claimed in any preceding claim, wherein the valve plate consists of sheet metal.

13. A valve as claimed in any preceding claim, wherein the housing includes a flange for securing the housing to the outlet aperture of the container, and includes walls, inclined at their lower end, defining a discharge shaft, in which walls the cam is mounted.

14. A valve as claimed in claim 13, when appendent to claim 2, wherein the rollers are situated in the walls of housing.

15. A closure valve substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.