GB2037367A - Improvements in and Relating to Pumps - Google Patents

Abstract

A manual pump suitable for dispensing liquids from containers comprises a hollow barrel 3 with a hollow plunger 6 mounted therein. The bore 17 of the plunger 6 forms an outlet passage from the pump, an outlet valve 24 being provided at the end of the plunger 6 within the barrel. An inlet valve 5 is provided at the lower end of the barrel 3. Both the inlet and outlet valves 5, 25 are essentially pressure differential operative valves. <IMAGE>

Description

SPECIFICATION Improvements in and Relating to Pumps This invention relates to pumps and in particular to manual pumps suitable for extracting liquid from containers.

The intention of this invention is to provide an effective manual pump of simple construction which can be produced in large numbers without the need of expensive tooling. While initially the pump is intended for utilisation with container stored liquids such as dispensed at service stations and in factories and paint shops it is envisaged that the pump will have wider applications, for example, for use as a bilge pump on a pleasure craft.

According to one aspect of this invention there is provided a manual pump comprising a hollow barrel with a pressure differential operative inlet valve at an inlet end thereof and housing a hollow reciprocally operative plunger axially mounted through a gland sealing the other end of the barrel, the bore of the plunger forming an outlet passage of the pump with the inner end thereof also being controlled by a pressure differential operative outlet valve, the valve actions being in opposition to one another with, in use, when charged, withdrawal of the plunger opening the inlet valve and closing the outlet valve to thus recharge the barrel, the inlet valve closing solely owing to gravitational forces or additionally with depression of the plunger which also opens the outlet valve to transfer the contents of the barrel to the outlet passage to discharge.

In further describing the invention reference is made to the accompanying drawings of a preferred embodiment wherein; Figure 1 is a side elevation partly truncated and partly in cross-section, and Figure 2 is a cross-sectional view of the outlet valve.

A pump barrel 3 is preferably formed from a length of standard size plastics tubing, the length of barrel 3 being adapted to be commensurate to a particular application, for example, to be commensurate to the depth of a liquid storage container to be discharged by the pump. It is envisaged that most barrels 3 will be approximately between 500mm and one(1) metre in length. Preferably a P.V.C. plastics tubing is selected having a wall of considerable thickness to facilitate mounting an inlet valve 5 and a plunger 6 thereto as described hereinafter.

At an inlet end, in use a lower end of the barrel 3, the pressure differential operative inlet valve 5 is mounted. Preferably the valve 5 comprises a generally cylindrical shaped body machined in metal to incorporate at one end an externally screw-threaded section 7. A matching internally screw-threaded section 8 is provided at the end of barrel 3 thus enabling mounting of valve 5 thereto.

It is primarily the need to provide sufficient material for the formation of screw-threaded section 8 and a corresponding external screwthreaded section (not depicted) at the opposing end of barrel 3 to receive a gland nut 14 that barrel 3 needs to have a substantial wall thickness. In that screw-threaded end section 7 of the valve 5 a bore 9 is formed, the diameter of bore 9 at that end being its largest and, medially of the valve body, reducing in diameter by way of a conically tapering section 10 to terminate with a reduced diameter bore section conjoining with the outer end of the valve to form an inlet port 12.

That lower end of the valve 5 is preferably formed with at least one diametrically extending open ended channel 30 which conjoins with port 12.

Thus, if that end of the pump is rested on a flat surface, for example, the bottom of a container, port 12 is not closed-off.

A ball 11, preferably a metal ball, is housed within the inner larger diameter section of bore 9 to gravitationally seat on the conical shaped wall section 10 thereof to thus close-off the inlet port 12. A spring clip 14, for example, a circlip, is mounted in the inner end of bore 9 to entrap ball 11 therein.

The plunger 6 has a stem 13 formed from metal tubing and is of a length commensurate to the length of barrel 3 plus an additional amount to form a handle 25 as described hereinafter. Stem 13 is mounted in the barrel 3 through sealed gland nut 14 mounted at the end of barrel 3 distal of the inlet valve 5 by way of engaging screwthreads in conventional manner. A suitable annular seal 1 5 is provided about the inner end terminating section of stem 13 to impinge onto the bore of barrel 3 and thus form the plunger 6.

Seal 15 is preferably an "0" ring mounted in an annular groove 16 formed externally of the body of an inlet valve 24 mounted to that end of the stem 1 3 and described in more detail hereinafter.

The bore 1 7 of the stem 13 provides an outlet passage from the barrel 3, the inner end of the bore 17 being controlled by the outlet valve 24 which is also primarily a pressure differential operative valve. Preferably the outlet valve 24 is a ball valve substantially the same as inlet valve 5 and more particularly with reference to Figure 2 comprises a ball 1 9 retained by a clip 20 in a bore 21 to seat on a conically shaped wall section 22 thereof to close an outlet port 23. Screwthreaded sections 1 8 are provided on the end of stem 13 and valve 24 to enable mounting of the two together.

The outer terminating section of the plunger stem 13 is formed into a diametrically, relative to the barrel 3, disposed handle 25 by shaping that terminating section of the stem 13 to an arcuate crook or pronounced swan-neck configuration.

That section of the stem 1 3 is preferably sheathed with a length of plastics tubing 26 to facilitate gripping.

Preferably an outlet hose 27 is attached to the outer end of stem 13 by way of a spigot connector 28 engaged in that end of stem 13.

The minimum length of hose 27 is related to the length stroke of the pump as to allow sufficient free-play to compensate for the reciprocal action of the plunger 6. For example, should a user hold the handle 25 in one hand and the outlet end of the hose 27 in the other hand in a convenient manner the hose 27 will be of sufficient length as not to inhibit the reciprocal pumping action of the plunger 6. Spring clips 29 are preferably provided adjacent each end of hose 27 to facilitate attachment of those ends as required.

Preferably a lid 31 is provided on barrel 3 to facilitate mounting of the pump to a container. Lid 31 may comprise a sheet metal disc with a central mounting aperture 32 to receive barrel 3.

A "U" shaped clip 33 is provided internally of the lid 31 and also incorporates barrel receiving apertures in the arms thereof. The free arm of clip 33 frictionally grips, owing to its flexibility, the outer wall of barrel 3. Lid 31 incorporates a depending skirt 34 in which radially disposed container attachments screws 35 are mounted.

With lid 31 covering the open end of a container and with the skirt 34 outward of the rim thereof, screws 35 can be adjusted inwardly to clamp the lid 31 thereto. Preferably a spigot-like connector 36 is mounted through lid 31 whereby at the end of a dispensing operation hose 27 can be attached thereto by way of clip 29 to return residual liquid with the pump by drainage or, following withdrawal of the barrel 3 from the parent liquid source, with pumping.

Alternatively, a conventional screw-threaded drum bung (not shown) can be formed with an aperture therethrough to accommodate barrel 3.

Claims (8)

Claims

1. A manual pump comprising a hollow barrel with a pressure differential operative inlet valve at an inlet end thereof and housing a hollow reciprocally operative plunger axially mounted through a gland sealing the other end of the barrel, the bore of the plunger forming an outlet passage of the pump with the inner end thereof also being controlled by a pressure differential operative outlet valve, the valve actions being in opposition to one another with, in use, when charged, withdrawal of the plunger opening the inlet valve and closing the outlet valve to thus recharge the barrel, the inlet valve closing solely owing to gravitational forces or additionally with depression of the plunger which also opens the outlet valve to transfer the contents of the barrel to the outlet passage to discharge.

2. A manual pump as claimed in Claim 1 wherein the outer terminating section of the plunger is shaped into an arcuate crook configuration to form a diametrically disposed plunger handle.

3. A manual pump as claimed in either Claim 1 or Claim 2 wherein an outlet hose is attached to the outer end of the plunger, the length of hose being at least twice the length of the stroke of the pump.

4. A manual pump as claimed in any one of the preceding claims wherein both valves comprise separate units mounted to the barrel and stem respectively and each comprising a body with a bore therethrough, the bore having a larger diameter section at the inner end thereof leading to a medial section of a conical configuration, the defining bore wall so tapering to terminate with an inlet port in the outer end of the valve and a ball being entrapped in the larger diameter section of the bore to seat on the conically tapering wall to close the inlet port.

5. A manual pump as claimed in Claim 3 or Claim 4 incorporating a lid frictionally attached to the barrel and clampable to the rim defining a container opening by way of screws in a depending peripheral skirt on the lid, the lid incorporating an aperture therethrough to receive the outlet end of the hose enabling return to the parent liquid supply of residual liquid in the pump by drainage and/or operation of the pump.

6. A manual pump as claimed in Claim 4 or Claim 5 wherein the barrel is formed from a length of plastics tubing and the plunger seal comprises an "0" ring mounted in an external annular groove formed in the body of the outlet valve as to impinge onto the wall of the bore of the barrel.

7. A manual pump as claimed in Claim 4, 5 or 6 wherein the outer end of the inlet valve incorporates at least one open ended channel conjoining with the inlet port thereof.

8. A manual pump substantially as herein described with reference to the accompanying drawings.