GB2328983A - Drum pumps - Google Patents

Abstract

A drum pump is actuated by a manually-operated pivotable handle 1 which is coupled to a piston rod 7 via a link 18, or a lever. The pump has a plastics housing comprising an upper detachable unit (81, fig 1) with a spout 3, and a cylindrical lower body (13, fig 1) within which a piston 12 reciprocates. The upper unit (81) supports the handle 1 and may have internal guides to guide the movement of the link 18. The piston rod 7 is guided through a sealed bearing 49 in an end wall of the upper unit (81). The piston 12 co-operates with valve members 8,11 to transfer liquid from the container through the pump. A screw threaded boss 59 on a plug 58 of the body (13) fits into a threaded aperture in a liquid filled drum. The coupling 18 between the handle 1 and piston rod 7 is intended to overcome problems of distortion and leakage.

Description

IMPROVEMENTS IN PUMPS The present invention relates to pumps and more particularly to so-called "drum pumps which are used to dispense some liquid usually stored in bulk, such as oil or a liquid, or solution containing a chemical agent, used, for example, for cleaning or in agriculture, from a bulk storage container, such as a tank or drum.

Such a pump is usually fitted to the container by screwing into a threaded bore in the latter. A manually operated handle is then used to pump the liquid from the container for discharge through a spout leading from the pump.

Drum pumps of various designs have been manufactured from metallic castings and more recently from plastics material. The latter is preferred particularly since these pumps tend nowadays to be adopted as disposable items with a limit life and the cost needs to be kept low.

The known pumps made from plastics material all use a piston which co-operates with a pair of valves as the piston moves within a cylindrical chamber. The manually operable handle is mounted for raising and lowering motion and is used to displace the piston Hitherto the mounting of the handle and the mode of its coupling to the piston rod have caused problems with distortion and leakage.

A general object of the invention is to provide an improved drum pump.

A pump constructed in accordance with the invention comprises a cylindrical body containing a piston carried by a piston rod, valve means for co-operating with the displacement of the piston during use to cause liquid to pass through the pump from an inlet connected to a container to an outlet for discharge from the pump and a manually operable handle for displacing the piston rod and the piston wherein the handle is connected to the piston rod with a toggle linkage. The toggle linkage can take the form of a single lever pivotably mounted at one end to the piston rod and pivotably mounted at the other end to the handle. The cylindrical body may adjoin a detachable unit with a spout acting as the outlet and carrying the handle. Conveniently the detachable unit has a narrow box-like rectangular sub-housing or section which merges into the handle and the spout and which contains the toggle linkage and the associated pivot joints for the handle. Preferably the sub-housing has internal guide means for guiding the movements of the toggle linkage. A sealed bearing in an end wall adjacent the cylindrical body may slidably support the piston rod.

In another aspect there is provided a pump composed of detachably interconnected upper and lower housing components, the upper housing component having an outlet and pivotably supporting a manually-operable handle and the lower housing component containing a piston in a cylindrical chamber and co-operating valve means which serve to transfer fluid from an inlet of the pump to the outlet as the piston is displaced by operation of the handle; wherein the piston is carried by a piston rod guided by a sealed bearing outside the chamber and the upper housing component contains a lever or lever system for coupling the piston rod to the handle.

The invention may be understood more readily, and various other features and aspects of the invention may become apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings wherein: Figure 1 is a side view of a pump constructed in accordance with the invention; Figure 2 is a front view of the pump shown in Figure 1; Figure 3 is a sectional side view of the pump shown in Figures 1 and 2 with the handle in one operating position, and Figure 4 is a sectional side view of pump shown in Figures 1 to 3 with the handle in another operating position.

As shown in Figures 1 and 2 of the drawings, a pump 90 constructed in accordance with the invention is constructed mainly from synthetic plastics components and exhibits a main body 91 with a manually-actuable handle 1 and a dispensing spout 3 for discharging a liquid such as oil. The handle l and the spout 3 are located opposite one another on an upper detachable unit 80 which has a sub-housing section 81 of generally narrow rectangular configuration. The section 81 merges in with the spout 3 and the handle as shown in Figure 2.

The section 81 has side walls 82 fixed together with the aid of screws 83. These side walls 82 merge into a domed cover 33 which surmounts a cylindrical lower body 13. A releasable screw-threaded ring or nut 100 below the cover 33 serves to secure the unit 80 to the cylindrical body 13. The cylindrical body 13 has a similar screw threaded ring or nut 10 at the base and a depending screw-threaded boss 84 which projects below the ring 10. During use, the screw-threaded boss 84 would be inserted into a screw-threaded hole in a container such as a drum which stores the liquid to be pumped so that the pump 90 is mounted in a convenient location for operation of the handle 1. The ring or nut 10 can be used to rotate the pump 90 to tighten the boss 84 into the screw-threaded hole. By raising and lowering the handle 1 a user can pump liquid out from the container for discharge through the spout 3. As shown in Figures 3 and 4, the spout 3 contains a gauze disc 4 to prevent drips escaping from the spout 3 after the handle 1 has been operated and the liquid pumped through the pump 90. The disc 4 is held in place with a detachable lining plug 5.

As shown in Figures 3 and 4, the interior of the cylindrical body 13 forms a working chamber 55 which leads through an aperture in an upper end wall 51 and through a multisection tube 56 to the spout 3. The end wall 51 is formed at the bottom of the unit 80. The end wall 51 has a locating lip 6 which fits inside the body 13 and an external lip 2 which engages on a shoulder 14 formed on the outside of the body 13 and supported by flanges 16.

An o-ring 15 serves to seal between the lip 2 and the adjacent external region of the body 13.

A piston assembly 48 composed of a piston 12 with a sliding seal 22 in a grooved periphery is mounted for sliding within the chamber 55 of the cylindrical body 13. The piston 12 possesses apertures 85. The piston 12 is carried by a piston rod 7, which extends concentrically along the body 13. The piston rod 7 has a screw threaded end region which receives a nut 9 used to fix the piston 12 to the rod 7. The piston rod 7 also has a reduced diameter end portion 57 on which an upper valve member 8 is located for slidable movement.

The piston rod 7 is guided through the end wall 51 and within a bearing 49 containing a seal in a bushing 17 formed on the outside of the end wall 51 of the unit 80. The body 13 has another end wall 86 with a frusto-conical cavity 87. This end wall 86 adjoins a plug member 58 formed with the screw threaded boss 84. The screw-threaded ring 10 supports the plug member 58.

An inner tubular section 59 of the plug member 58 contains the stem of a further valve member 11 which is slidably mounted within a bore 60 in the base of the cavity 87. The tubular section 59 can be coupled to pipe or tube extending into the associated storage container. The valve member 11 has a sealing disc 61 which overlies the base of the cavity 87 and extends over an aperture 62 therein. The aperture 62 communicates with the cavity 87 and with the apertures 85 in the piston 12 for the passage of liquid when the valve member 11 is open.

The upper end of the piston rod 7 outside the chamber 55 is connected with a pivot joint 63 to a toggle lever 18 and the lever 18 is connected with a pivot joint 64 to the end of the handle 1 within the upper unit 80. The handle 1 is connected with a pivot joint 65 to the side walls 82 of the section 81 of the unit 80. The lever 18 can simply float but the internal sides of the walls 82 can be provided with ribs acting as guide means to guide the movement of the handle and the lever 18.

Figures 3 and 4 show the handle 1 in its two extreme operating positions. In Figure 3 the handle 1 has been raised to force the piston rod 7 downwardly until the piston 12 abuts on the end wall 86. The disc 61 of the valve member 11 closes off communication between the tubular section 59 of the plug member 58 and the cavity 87 whilst the valve member 8 is raised from the piston 12 to open the apertures 85 to the working chamber 55. As the handle 1 is lowered to draw the piston rod 7 and the piston 12 upwardly liquid is induced to flow through the inner tubular section 59 and through the aperture 62 into the cavity 87. The valve member 11 is raised and open whilst the valve member 9 seats in a recess 86 in the piston 12 to close off the apertures 85 therein. In a position shown Figure 4 the piston 12 is in its uppermost position and the working chamber 55 is filled with liquid. The valve member 11 in the recess 86 in the piston 12 and closed whilst the valve member 11 is fully raised and open. As the handle 1 is raised again to force the piston 12 downwardly pressure in the chamber 55 ensures the valve member 11 moves downwardly and become closed while the valve member 8 is forced, upwardly and is opened. Liquid flows through the apertures 85 in the piston 12 and the liquid is then forced to flow through the end wall 51 and the tubing 56 to the spout 3.

Thus by successively raising and lowering the handle 1 liquid can be dispensed from the spout 3 in doses.

The provision of the lever 18 protected inside the sub-housing 81 is advantageous in ensuring that the piston rod 7 and the sealed bearing 49 are not subjected to undue wear and distortion.

Claims (11)

Claims

1. A pump comprising a cylindrical body containing a piston carried by a piston rod, valve means for co-operating with the displacement of the piston, during use, to cause liquid to pass through the pump from an inlet connected to a container to an outlet for discharge and a manually-operable handle for displacing the piston rod and the piston; wherein the handle is connected to the piston rod with a toggle linkage.

2. A pump composed of detachably interconnected upper and lower housing components, the upper housing component having an outlet and pivotably supporting a manually-operable handle and the lower housing component containing a piston in a cylindrical chamber and cooperating valve means which serve to transfer fluid from an inlet of the pump to the outlet as the piston is displaced by operation of the handle; wherein the piston is carried by a piston rod guided by a sealed bearing outside the chamber and the upper housing component contains a lever or lever system for coupling the piston rod to the handle.

3. A pump according to claim 1 or 2, wherein the lever or lever system or the toggle linkage is a single lever pivotably mounted at one end to the piston rod and pivotably mounted at the other end to the handle.

4. A pump according to claim 1, wherein the cylindrical body adjoins a detachable unit with a spout acting as the outlet and carrying the handle.

5. A pump according to claim 4 wherein the detachable unit has a narrow box-like rectangular sub-housing or section which merges into the handle and the spout and which contains the toggle linkage.

6. A pump according to claim 5, wherein the sub-housing has internal guide means for guiding the movements of the toggle linkage.

7. A pump according to claim 5 or 6, wherein the sub-housing is provided with a sealed bearing in an end wall adjacent the cylindrical body, the bearing serving to slidably support the piston rod.

8. A pump according to any one of claims 5 to 7, wherein a releasable screw-threaded ring or nut serves to secure the sub-housing to the cylindrical body.

9. A pump according to any one of claims 5 to 8, wherein the cylindrical body has a depending tubular member which serves as the inlet when operably engaged into the container during use.

10. A pump according to any one of the preceding claims wherein the piston is provided with apertures and the valve means is composed of a valve member slidably mounted on the piston rod to overlay the piston and close-off the apertures from one side and a tappet valve on the other side of the piston which opens and closes a passageway leading to the inlet.

11. A pump substantially as hereinafter described with reference to, and as illustrated in, the accompanying drawings.