GB2250781A

GB2250781A - Dispenser of viscous materials

Info

Publication number: GB2250781A
Application number: GB9026079A
Authority: GB
Inventors: Philip Wilmott
Original assignee: Colebrand Ltd
Current assignee: Colebrand Ltd
Priority date: 1990-11-30
Filing date: 1990-11-30
Publication date: 1992-06-17
Anticipated expiration: 2010-11-30
Also published as: GB2250781B; GB9026079D0

Abstract

The contents of a reservoir 12 are pressurised by a coil spring biased diaphragm 14 towards an outlet in which is a spring loaded plunger 26 having a probe 28 extending towards the position of a target at which the contents of the reservoir may be directed. When the probe does not engage the target, the spring loaded plunger 26 is biased to its rest position in which a valve 23, 24 in the outlet is closed. When the probe engages the target, the plunger moves to open the valve and allow the contents of the reservoir to flow through the outlet past the plunger towards the target. The plunger 26 is hollow, its bore providing the outlet for the material being dispensed. <IMAGE>

Description

SUPPLY OF VISCOUS MATERIALS This invention relates to apparatus for supplying viscous materials. Viscous materials such as lubricating grease can be supplied from a grease gun, in which the material is stored under pressure in a reservoir and flow of the material through an outlet from the reservoir is controlled by a trigger. The trigger may simply be used to open a valve in the outlet to allow flow of the material through the outlet or it may be used to pump material from the reservoir to the outlet. In a simpler apparatus the outlet remains open and the flow of material from the reservoir is controlled by controlling the pressure on the reservoir, flow being stopped by releasing the pressure applied to the reservoir.

The present invention relates to apparatus of the type in which pressure is applied continuously to the reservoir and flow of material from the reservoir is controlled by a valve in the outlet. Unlike the known arrangement described above, the valve is controlled by a position sensor, responsive to the apparatus being brought close to the target to which the material is to be supplied. One such sensor is a plunger which is depressed by the target as the apparatus is brought close to it, depression of the plunger causing the valve to open to release flow of material from the reservoir through the outlet. The plunger may be located in the outlet itself, the material flowing past the depressed plunger. Preferably the plunger is biassed towards a rest position so that it closes the valve when the apparatus is moved away from the target.

An example of the invention wili now be described with reference to the accompanying drawings, in which: Figure 1 shows an exploded view of a viscous material dispenser, and Figure 2 shows the dispenser assembled.

A reservoir 11 for viscous materials such as an electrically conductive couplant comprises a domed cylindrical body 12 fitting into a base 13 formed with a central outlet. A diaphragm 14 within the cylindrical body 12 is biassed towards the base 13 by a coil spring 15 to exert pressure on material contained within the reservoir 11 below the diaphragm 14. An O-ring 16 seals the edge of the diaphragm 14 to the cylindrical wall of body 12. A nipple 17 is provided on the side of the base through which material can be injected into the reservoir, the nipple 17 containing a conventional one-way valve to prevent escape of material from the reservoir 11 therethrough.

A hollow coupler 21 screws on to the base 13 of the reservoir 11 and a hollow nozzle body 22 screws on to the coupler 21. An O-ring 23 forms a valve seat on the nozzle body 22 and a ball 24 biassed by a relatively heavy coil spring 25 reacting on the coupler 21 forms the valve body associated with the seat, A sensing plunger 26 provided with two axially spaced O-rings 27 is mounted for sliding movement within the nozzle body 22, being retained by a lip 28 on the lower end of the body and being biassed towards that lip by a relatively light coil spring 29 reacting on the ball 24. The plunger 26 is hollow, its bore 31 providing the outlet for the material.

In operation, the dispenser contains viscous material within the reservoir 11 into which it has been fed through the nipple 17. The coil spring 13 pressurises the material.

The pressure of the material and of the heavy spring 25 keeps the ball 24 on its seat so that material cannot escape past the plunger 26 and through the nozzle body 22.

When the dispenser is brought close to a target to which the material is to be applied, the plunger 26 engages the target and is moved against the bias of the light spring 29 into contact with the base of the ball 24, lifting it off its seat so that material can flow through the valve and the plunger 26 and on to the target. When sufficient material has been applied to the target, the dispenser is moved away and the plunger 26 is returned to its rest position as illustrated by the combined pressures of the springs 23 and 29 and of the material, so that the ball 24 returns to its seat and prevents further flow of material from the reservoir.

Although a combined outlet member and sensing device is preferred, the two functions could be provided by separate components. The plunger should be located near the outlet in order to be actuated by the proximity to the target, but it does not have to define or be located in the outlet passage for the material. The sensing of the proximity of the target can be achieved by non-mechanical means, rather than by the plunger illustrated.

Claims

Ciao:

1. Apparatus for supplying viscous materials comprising a reservoir having an outlet, means for applying pressure to the contents of the reservoir, a valve for controlling the flow of the reservoir contents through the outlet and sensing means responsive to the distance of the sensor from a target for controlling said valve.

2. Apparatus as claimed in Claim 1 wherein said sensor comprises a plunger adapted to contact said target and to trove fran a rest position in which the valve is closed to another position on engagement of the plunger with the target in which position the valve is opened.

3. Apparatus as claimed in Claim 2 wherein said plunger is arranged within the outlet so that viscous material fram the reservoir can flow past it when the valve is opened.

4. Apparatus as claimed in Claim 2 or Claim 3 comprising means for biasing said plunger to its rest position so that it closes the valve when the apparatus is moved away from a target.

5. Apparatus for supplying viscous materials substantially as hereinbefore described with reference to the accompanying drawings.