GB2063423A - Slide Closure Assembly - Google Patents

Abstract

A side closure assembly for use in controlling gravity feed from storage hoppers comprises a door 2 which is displaced in a horizontal plane to open and close an opening 1. In order to prevent jamming and sticking of the door in the opening, the door 2 and the associated opening 1 are both tapered in the direction of forward closing movement of the door such that, on opening, the door moves across a progressively increasing door opening. The taper required can be very small and is typically in the region of 1 DEG . <IMAGE>

Description

SPECIFICATION Slide Closure Assembly The present invention concerns slide closure assemblies and in particular slide doors and the like for use in controlling the discharge chutes of bulk feed hoppers and the like.

It is conventional practice to instal a slide door slidable in substantially a horizontal plane at the bottom of a gravity feed storage hopper. On sliding the door to an open position the contents of the hopper can fall through the opening into a receiver. For example, in the quarrying industry, a truck can be loaded by driving beneath the hopper and allowing a load to fall thereinto upon opening the slide door.

Existing slide doors suffer certain drawbacks. If the door itself is not a close fit within its frame then seepage and loss of material from the hopper can take place around the edges of the door. Alternatively, if the door is too tight a fit in its frame jamming can occur and the door can become immovable and incapable of operation.

The present invention seeks to overcome the disadvantages of existing slide doors for bulk feed gravity hoppers and according to the invention there is provided a slide door assembly in which the door and the associated door opening or frame are tapered in the direction of forward closing movement of the door such that the door on opening moves across a progressively increasing door opening.

The taper required can be very small and is sufficient to prevent jamming and sticking of the door as experienced with existing known slide door assemblies. When fully closed the door is a close fit in its frame and effectively seals the opening.

The invention will be described further, by way of example, with reference to the accompanying drawings; in which: Fig. 1 is a diagrammatic plan view of a door assembly to illustrate the principle of the invention.

Fig. 2 is a section along line A-A in Fig. 1.

With reference to the drawings, a slide door assembly comprises a frame structure having a first portion with an opening 1 therethrough closable by a slide door 2 and a second portion forming a housing 3 for the slide door when the latter is moved to a withdrawn position to clear the opening. The frame can be formed from channei-shaped side members 4. The assembly' is adapted to be fitted to the base of a storage hopper and for this purpose the frame members about the opening are provided with holes 5 whereby the structure can be bolted to the hopper. Rollers 6, conveniently of nylon, are journalled along opposite sides of the opening 1 to support the slide door 2 in moving between its open and closed positions. Above the path of the door the opening is provided with a peripheral edge bars 7 which overlap the edges of the door.

As seen in Fig. 1 the door opening in the frame assembly and the slide door itself are tapered in a direction of closing movement of the door. The degree of taper is exaggerated in Fig. 1 for clarity.

In moving to an open position the slide door moves across a progressively increasing opening and in Fig. 1 the dotted outline shows the slide door in approximately a half open position to illustrate this effect. In opening the slide door enters the housing which can be provided with cover plates. The slide door can be moved by a double acting piston and cylinder assembly 8 mounted at the end of the housing with a piston rod 9 connected to the slide door. Preferably the piston and cylinder assembly is operated pneumatically. When fully closed the slide door 2 is a tight abutting fit in the opening and material in the hopper cannot escape around the edges of the door.

As mentioned, the degree of taper is exaggerated in the drawings. As an example only, the angle of taper can be in the region of 1 0.

The assembly is intended primarily for use with bulk storage hoppers containing, for example, granular, pulverulent or powder materials. One particular application is for fitting to storage hoppers at gravel pits and quarries although it will be realised that the assembly is not restricted to such use.

Claims

1. A slide door assembly comprising a door and means defining an associated door opening, the door and the door opening both being tapered in the direction of forward closing movement of the door such that, on opening, the door moves across a progressively increasing door opening.

2. A slide door assembly as claimed in claim 1 in which the door opening is defined by one portion of a frame structure, a second portion of which defines a housing in which the door is received when it has been withdrawn to a position to clear the opening.

3. A slide door assembly as claimed in claim 1 or 2 including a plurality of edge bars positioned to lie above the path of the door such as to overlap the edges of the door when the latter is in its position closing the opening.

4. A slide door assembly as claimed in claim 1, 2 or 3 in which the taper angle of the door and opening is in the region of 1 .

5. A slide door assembly as claimed in any of claims 1 to 4 when fitted in a substantially horizontal plane at the lower end of a gravity feed storage hopper.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Slide Closure Assembly The present invention concerns slide closure assemblies and in particular slide doors and the like for use in controlling the discharge chutes of bulk feed hoppers and the like. It is conventional practice to instal a slide door slidable in substantially a horizontal plane at the bottom of a gravity feed storage hopper. On sliding the door to an open position the contents of the hopper can fall through the opening into a receiver. For example, in the quarrying industry, a truck can be loaded by driving beneath the hopper and allowing a load to fall thereinto upon opening the slide door. Existing slide doors suffer certain drawbacks. If the door itself is not a close fit within its frame then seepage and loss of material from the hopper can take place around the edges of the door. Alternatively, if the door is too tight a fit in its frame jamming can occur and the door can become immovable and incapable of operation. The present invention seeks to overcome the disadvantages of existing slide doors for bulk feed gravity hoppers and according to the invention there is provided a slide door assembly in which the door and the associated door opening or frame are tapered in the direction of forward closing movement of the door such that the door on opening moves across a progressively increasing door opening. The taper required can be very small and is sufficient to prevent jamming and sticking of the door as experienced with existing known slide door assemblies. When fully closed the door is a close fit in its frame and effectively seals the opening. The invention will be described further, by way of example, with reference to the accompanying drawings; in which: Fig. 1 is a diagrammatic plan view of a door assembly to illustrate the principle of the invention. Fig. 2 is a section along line A-A in Fig. 1. With reference to the drawings, a slide door assembly comprises a frame structure having a first portion with an opening 1 therethrough closable by a slide door 2 and a second portion forming a housing 3 for the slide door when the latter is moved to a withdrawn position to clear the opening. The frame can be formed from channei-shaped side members 4. The assembly' is adapted to be fitted to the base of a storage hopper and for this purpose the frame members about the opening are provided with holes 5 whereby the structure can be bolted to the hopper. Rollers 6, conveniently of nylon, are journalled along opposite sides of the opening 1 to support the slide door 2 in moving between its open and closed positions. Above the path of the door the opening is provided with a peripheral edge bars 7 which overlap the edges of the door. As seen in Fig. 1 the door opening in the frame assembly and the slide door itself are tapered in a direction of closing movement of the door. The degree of taper is exaggerated in Fig. 1 for clarity. In moving to an open position the slide door moves across a progressively increasing opening and in Fig. 1 the dotted outline shows the slide door in approximately a half open position to illustrate this effect. In opening the slide door enters the housing which can be provided with cover plates. The slide door can be moved by a double acting piston and cylinder assembly 8 mounted at the end of the housing with a piston rod 9 connected to the slide door. Preferably the piston and cylinder assembly is operated pneumatically. When fully closed the slide door 2 is a tight abutting fit in the opening and material in the hopper cannot escape around the edges of the door. As mentioned, the degree of taper is exaggerated in the drawings. As an example only, the angle of taper can be in the region of 1 0. The assembly is intended primarily for use with bulk storage hoppers containing, for example, granular, pulverulent or powder materials. One particular application is for fitting to storage hoppers at gravel pits and quarries although it will be realised that the assembly is not restricted to such use. Claims

1. A slide door assembly comprising a door and means defining an associated door opening, the door and the door opening both being tapered in the direction of forward closing movement of the door such that, on opening, the door moves across a progressively increasing door opening.

2. A slide door assembly as claimed in claim 1 in which the door opening is defined by one portion of a frame structure, a second portion of which defines a housing in which the door is received when it has been withdrawn to a position to clear the opening.

3. A slide door assembly as claimed in claim 1 or 2 including a plurality of edge bars positioned to lie above the path of the door such as to overlap the edges of the door when the latter is in its position closing the opening.

4. A slide door assembly as claimed in claim 1, 2 or 3 in which the taper angle of the door and opening is in the region of 1 .

5. A slide door assembly as claimed in any of claims 1 to 4 when fitted in a substantially horizontal plane at the lower end of a gravity feed storage hopper.