GB2295638A

GB2295638A - Material flow device

Info

Publication number: GB2295638A
Application number: GB9424193A
Authority: GB
Inventors: David Bone
Original assignee: BROOKMEX Ltd
Current assignee: BROOKMEX Ltd
Priority date: 1994-11-30
Filing date: 1994-11-30
Publication date: 1996-06-05
Also published as: GB9424193D0

Abstract

An infinitely variable control device for controlling the passage of materials of all types, for locking the movement of linear solids, or for the extrusion of plastics materials. The device comprises two adjacent cylinders 4 which have circumferential grooves which vary in depth about the circumference and together define an orifice communicating with inlet 2 and outlet 3. The simultaneous rotation of the cylinders causes the orifice to be varied in infinitely small increments. <IMAGE>

Description

INFINITELY VARIABLE MATERIAL FLOW DEVICE This invention relates to a material flow control device Typically the rate of flow of material is controlled by valves using movable gates, flaps (butterflies), spheres or plugs. Common features of such valves are that they do not close in even increments and that they frequently have a multiplicity of moving parts.

The first feature may provide for uneven control, the second relates to the expense of manufacture.

According to the present invention there is provided a material flow device that permits the material that it is designed to control to be regulated through an infinitely variable orifice device which, in its simplest form, comprises two adjacent parallel and contiguous cylinders both capable of revolving in an interlocked manner. Each cylinder has a semi-circular trough or groove running around its circumference at the mid-point and varying in radius from zero to a predetermined maximum = limited limited by the radius of the cylinder. The inner surface of the groove thus forms a segment of a spiral of increasing radius. The cylinders are configured so that they revolve in a symmetrical way (i.e. so that the profile of each groove on either cylinder when in contact is of similar dimensions). The grooves thus form the two halves of a circular orifice.As the cylinders rotate in the direction of the niminishing groove the orifice becomes progressively smaller. If the cylinders are rotated in the reverse sense the orifice becomes larger until it reaches its designed maximum. Flow control of the material is achieved directly by the simultaneous rotation of the cylinders.

A specific embodiment of the invention will now be described by way of illustration with reference to the accompanying sketches in which: Figure 1 illustrates the housing and position of the drive and seals.

Figure 2 illustrates the gearing of the cylinders and the worm gear.

Referring to the drawings the body of the device (1) is fitted with flanged inlets (2) and outlets (3) for connection to a material flow system. The main part of the body locates the cylinders (4) and holds them in contact. The seal (5) prevents material from passing through the device by any route other than the orifice.

The rotating cylinders (4) are connected by a keyed shaft (6) to cog wheels (7) outside the body of the device. Each shaft is sealed by a compressed nylon seal. The cog wheels (7) are interlocked thus ensuring simultaneous rotation of the cylinders (4) which are arranged so that the groove profiles in contact are of similar dimensions. The rotation of the cog wheels (4) (each in the reverse sense) is achieved by a worm gear (8) secured to one side of the device body parallel to the material flow. The body of the device, cylinders, cog wheels and worm gear can be fabricated of stainless steel, carbon steel, brass, machined nylon or any other suitable material. The seals could be of any suitable design including polymers, metal to metal for high pressure applications, or any other suitable material.

Claims

1) A material flow device that permits the material that it is designed to control to be regulated through an ipfinitely variable orifice device, in its simplest form, comprises two adjacent parallel and contiguous cylinders both capable of revolving in an interlocked manner. Each cylinder has a semi-circular trough or groove running around its circumference at the mid-point and varying in size from zero to a predetermined maximum limited by the radius of the cylinder.

The inner surface of the groove thus forms a segment of a spiral of increasing radius. The cylinders are configured so that they revolve in a symmetrical way (i.e. so that the profile of each groove on either cylinder when in contact is of similar dimensions). The grooves thus form the two halves of a circular orifice.

As the cylinders rotate in the direction of the diminishing groove the orifice becomes progressively smaller. If the cylinders are rotated in reverse sense the orifice becomes larger until it reaches its designed maximum. The material control is therefore effected directly by the simultaneous rotation of the cylinders.

2) A material control device, as claimed in claim 1, in which material flow is always controlled by a circular orifice.

3) A material control device, as claimed in claim 1, which consists of two moving parts or more.

4) A material control device, as claimed in claim 2 or claim 3, which can be used to grip and restrain the passage of flexible or rigid solids.

5) A material control device, as claimed in claim 2 or claim 3, which can be used to extrude plastic materials with a constant or varying cross-section.

6) A material control device, as claimed in claim 1 or claim 2, in which the rate of change of control area is directly proportional to the rotation of the control cylinders.

7) A material control device, substantially as described herein, with reference to Figures 1 k 2 of the accompanying drawings.