GB2328200A

GB2328200A - Apparatus for dispensing a fluent material

Info

Publication number: GB2328200A
Application number: GB9717000A
Authority: GB
Inventors: David Charles Gill
Original assignee: Nomix Chipman Ltd
Current assignee: Nomix Chipman Ltd
Priority date: 1997-08-11
Filing date: 1997-08-11
Publication date: 1999-02-17
Anticipated expiration: 2017-08-11
Also published as: GB9717000D0; GB2328200B

Abstract

Fluent material, for example a friction-enhancing substance for application to railway rails 8, is contained in a bag 20 and is dispensed onto the rail 8 through metering means in the form of a peristaltic pump 26. In order to maintain a supply of the material to the pump 26, biasing means in the form of a spring-loaded roller 36 engages the bag 20 to squeeze its contents towards its outlet, which is connected to a feed tube 22.

Description

APPARATUS FOR DISPENSING A FLUENT MATERIAL This invention relates to apparatus for dispensing a fluent material, and particularly, although not exclusively, a relatively viscous liquid, a gel or a pasty substance. In appropriate circumstances, however, the present invention may be applied to less viscous liquids, gases, and other fluent materials.

The present invention is particularly, although not exclusively, applicable to the dispensing of liquids, gels or pastes containing solid particles, such as sand or other gritty materials. Such substances are commonly applied to railway lines in order to improve the traction of a locomotive running on the railway lines. A substance used for this purpose is available under the name "SANDITE".

It is known to provide dispensing apparatus for SANDITE and similar materials on specially adapted locomotives or railway rolling stock. However, the use of such specially constructed vehicles is inconvenient when only a small length of track is to be treated on an occasional basis, for example when a length of track acquires a film of oil or other friction-reducing material. There is therefore a need for relatively inexpensive apparatus for apply SANDITE and similar materials to the track in railway stations and sidings on an occasional basis as the need arises.

According to the present invention there is provided apparatus for dispensing a fluent material, comprising a container for the material, having a variable internal volume, and biasing means which acts on the container to reduce its internal volume thereby to expel the fluid, the apparatus also comprising metering means having an inlet which communicates with the container and an outlet which communications with a delivery device of the apparatus, whereby the flow rate of fluid from the container to the delivery device is regulated by the metering means.

In a preferred embodiment, the metering means comprises a peristaltic pump. Alternatively, the metering means may comprise a valve having a variable flow cross-section, or a valve which periodically interrupts the flow through the metering means.

The peristaltic pump or the valve may be controlled in response to the travel speed of the apparatus over the surface to which the fluent material is to be applied. One way of achieving this is to provide the apparatus with a ground-engaging wheel, and driving a control element of the metering apparatus from the wheel.

The container for the fluent material may have a flexible wall on which the biasing means acts so as to tend to reduce the internal volume of the container.

The entire wall of the container may be flexible so that the container is in the form of a bag having an outlet connected to the inlet of the metering means.

The biasing means may comprise a bag engaging element which engages the bag, and actuating means for biasing the bag engaging element in a direction towards the bag outlet, thereby to expel the fluent material.

The bag may be supported on a reaction surface, the bag engaging element then being operable to press the bag wall towards the reaction surface so as to squeeze the contents towards the bag outlet as the bag engaging element is displaced towards the bag outlet by the actuating means.

The bag engaging element may be a roller which is mounted, for example, in guide tracks at each end, for travel in a direction parallel to the reaction surface.

The actuating means may be resilient, for example it may take the form of one or more springs.

In one possible embodiment, the apparatus may be adapted for dispensing a friction-enhancing material onto railway rails. The apparatus may have a handle enabling it to be moved along a rail by a pedestrian operator.

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 is a perspective view of apparatus for dispensing a fluent material; and Figure 2 shows a component of a peristaltic pump provided in the apparatus of Figure 1.

The apparatus shown in Figure 1 comprises a carriage 2 supported by a single front wheel 4 and a single rear wheel 6, each of which has a width substantially equal to that of a railway rail 8 on which the apparatus is to travel. A support 10 is secured to the carriage 2 and a handle 12 extends from the support 10 to a position where it can be conveniently grasped by a walking operator. The support 10 is generally channel-shaped having a web 14 extending between a pair of flanges 60. The support 10 is inclined downwardly towards the front, with respect to the intended direction of travel of the apparatus during operation. A cover 18 is pivotably connected to the support 10 at the lower end of the support 10. The cover 18 is shown raised in Figure 1, but, in normal operation, it would be lowered towards the web 14 so as to provide an enclosure.

Within this enclosure is situated a container 20 for a fluent material to be dispensed from the apparatus. The container 20 takes the form of a bag made from flexible sheet material and its contents, for the purpose of the embodiment shown in Figures 1 and 2, is SANDITE or a similar material containing solid particles, for application to the rail 8. The bag 20 has an outlet (not shown) which is connected to one end of a tube 22. The other end of the tube 22 is connected to an inlet 24 of metering means in the form of a peristaltic pump 26. The peristaltic pump has an outlet 27 which extends into the carriage 2 where it is connected to a delivery device (not shown) situated near to the rail 8, and from which the material from the container 20 is discharged onto the rail 8. The pump 26 comprises a rotor 28 which is drivingly connected to the wheel 6 so that rotation of the wheel 6 causes rotation of the rotor 28. The rotor 28 engages a tube 30 of the peristaltic pump. This tube 30 is mounted in a cassette 32 (Figure 2) which has holes 34 for securing the cassette within a housing of the peristaltic pump. At each end of the tube 30 there is a spigot 36 which engages the inlet and outlet 24, 27 of the peristaltic pump when the cassette is inserted.

The bag 20 is supported on the web 14 which serves as a reaction surface. The bag is engaged by biasing means, including a bag-engaging element in the form of a roller 36. This biasing means serves to reduce the internal volume of the bag 20 so as to squeeze the contents of the bag towards the bag outlet. Thus the fluent material is force fed to the inlet 24 of the peristaltic pump 26.

The roller 36 is supported at its ends in slots 38 formed in the flanges 16 of the support 10. Thus, the roller 36 is able to move up and down the support 10 in a direction parallel to the plane of the reaction surface 14. The roller 36 is biased towards the lower end of the reaction surface 14 by tension springs 40 provided on each side of the support 10.

To prepare the apparatus for operation, the cover 18 is raised and the roller 36 is pulled to its uppermost limit against the tension of the springs 40 to allow a bag to be placed on the reaction surface 14 below the roller 36. The bag outlet is connected to the tube 22.

The roller 36 is then placed over the top edge of the bag 20 and released, so that the springs 40 pull the roller 36 down over the bag until it is arrested by the body of the contents of the bag 20. Retaining means (not shown) may be provided to hold the bag 20 in position against the force applied by the roller 36.

When the peristaltic pump 26 is stationary, it closes the tube 30, so preventing any flow of the contents of the bag to the pump outlet 27. For use, the apparatus is placed on the rail 8 to be treated, and is pushed along the rail by an operator walking behind it. The resulting rotation of the rear wheel 6 causes corresponding rotation of the pump rotor 28, so creating a flow of the material from the bag to the dispensing device at a flow rate dependent on the speed of travel of the apparatus. As the material leaves the bag 20, the roller 36 can travel further down the slots 38, so maintaining pressure on the contents of the bag.

The structure of the pump cartridge shown in Figure 2 enables this cartridge to be removed easily, without requiring any major dismantling of the apparatus, for cleaning, repair or replacement.

It will be appreciated that the biasing means provided by the roller 36 and the springs 40 could take alternative forms. For example, a spring loaded plate could be provided beneath the cover 18 to apply a compressive force to the bag 20. Also, the need for the biasing force 20 is greatest at the start of operation, when it is necessary to prime the peristaltic pump 26. Consequently, the biasing means can be arranged so that it is under the control of the operator, and may be actuated only at the start of operation to prime the pump. During continuous operation, the biasing means can be released on the bag 20, the material on the bag 20 then being withdrawn only under the action of the pump 26, possibly assisted by gravity.

The peristaltic pump 26 serves as metering means to ensure that the appropriate quantity of the friction-enhancing material is applied to the rail 8.

Thus, even though the force applied to the roller 36 by the springs 40 will decrease as the roller 36 approaches the lower end of the reaction surface 40, the flow rate of the material onto the rail 8 will remain substantially constant throughout the operation.

Other forms of metering may be employed. For example, a variable orifice valve may be used, or a dosing device may be employed which intermittently opens and closes the fluid line between the outlet of the bag 20 and the dispensing device. One form of such a dosing device may be a rotary element which is driven by the wheel 6 and which has a transverse bore which is periodically aligned with an inlet and an outlet corresponding to the inlet and outlet 24, 26. The metering means may include a flowmeter responsive to the flow rate of material from the container to the dispensing device. The output of the flowmeter can then be used to control a variable valve or similar device to keep the flow rate within a desired range.

Although the present invention has been described with reference to the application of SANDITE and similar materials to railway rails, the basic principles underlying the invention can be applied to delivery equipment for other materials, for example herbicides in liquid form.

Claims

1. Apparatus for dispensing a fluent material, comprising a container for the material, having a variable internal volume, and biasing means which acts on the container to reduce its internal volume thereby to expel the fluid, the apparatus also comprising metering means having an inlet which communicates with the container and an outlet which communications with a delivery device of the apparatus, whereby the flow rate of fluid from the container to the delivery device is regulated by the metering means.

2. Apparatus as claimed in claim 1, in which the metering means comprises a peristaltic pump.

3. Apparatus as claimed in claim 1, in which the metering means comprises a valve which periodically interrupts flow through the metering means.

4. Apparatus as claimed in any one of the preceding claims, in which the metering means is controlled in response to the travel speed of the apparatus.

5. Apparatus as claimed in claim 4, in which the apparatus has a ground-engaging wheel, and in which the metering apparatus has a control element which is driven by rotation of the wheel.

6. Apparatus as claimed in any one of the preceding claims, in which the container has a flexible wall on which the biasing means acts.

7. Apparatus as claimed in claim 6, in which the container is a flexible bag having an outlet connected to the inlet of the metering means.

8. Apparatus as claimed in claim 7, in which the biasing means comprises a bag-engaging element which engages the bag, and actuating means for biasing the bag-engaging element in the direction towards the bag outlet, thereby to expel the fluent material from the bag.

9. Apparatus as claimed in claim 8, in which the bag is supported on a reaction surface, the bagengaging element being operable to press the bag wall towards the reaction surface.

10. Apparatus as claimed in claim 8 or 9, in which the bag-engaging element is a roller.

11. Apparatus as claimed in claim 10, in which the roller is mounted for travel in a direction parallel to the reaction surface.

12. Apparatus as claimed in any one of claims 8 to 11, in which the actuating means comprises at least one resilient element.

13. Apparatus as claimed in any one of the preceding claims which is adapted for dispensing a fluent material in the form of a viscous or pasty substance onto railway rails.

14. Apparatus as claimed in any one of the preceding claims which is adapted to be displaced over a surface onto which the fluent material is to be dispensed by means of a walking operator.

15. Apparatus for dispensing a fluent material substantially as described herewith with reference to, and as shown in, the accompanying drawings.

15. Apparatus as claimed in any one of the preceding claims, in which the container contains a friction-enhancing material comprising solid particles suspended in a viscous carrier.

16. Apparatus for dispensing a fluent material substantially as described herewith with reference to, and as shown in, the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS

1. Travelling apparatus for dispensing a fluent material, comprising a container for the material, having a variable internal volume, and biasing means which acts on the container to reduce its internal volume thereby to expel the fluid, the apparatus also comprising metering means which is responsive to the travel speed of the apparatus and which has an inlet which communicates with the container and an outlet which communicates with a delivery device of the apparatus, whereby the flow rate of fluid from the container to the delivery device is regulated by the metering means in response to the travel speed.

4. Apparatus as claimed in any one of the preceding claims, in which the apparatus has a groundengaging wheel, and in which the metering apparatus has a control element which is driven by rotation of the wheel.

5. Apparatus as claimed in any one of the preceding claims, in which the container has a flexible wall on which the biasing means acts.

6. Apparatus as claimed in claim 5, in which the container is a flexible bag having an outlet connected to the inlet of the metering means.

7. Apparatus as claimed in claim 6, in which the biasing means comprises a bag-engaging element which engages the bag, and actuating means for biasing the bag-engaging element in the direction towards the bag outlet, thereby to expel the fluent material from the bag.

8. Apparatus as claimed in claim 7, in which the bag is supported on a reaction surface, the bagengaging element being operable to press the bag wall towards the reaction surface.

9. Apparatus as claimed in claim 7 or 8, in which the bag-engaging element is a roller.

10. Apparatus as claimed in claim 9, in which the roller is mounted for travel in a direction parallel to the reaction surface.

11. Apparatus as claimed in any one of claims 7 to 10, in which the actuating means comprises at least one resilient element.

12. Apparatus as claimed in any one of the preceding claims which is adapted for dispensing a fluent material in the form of a viscous or pasty substance onto railway rails.

13. Apparatus as claimed in any one of the preceding claims which is adapted to be displaced over a surface onto which the fluent material is to be dispensed by means of a walking operator.

14. Apparatus as claimed in any one of the preceding claims, in which the container contains a friction-enhancing material comprising solid particles suspended in a viscous carrier.