WO1993015852A1

WO1993015852A1 - A portable high-pressure cleaner

Info

Publication number: WO1993015852A1
Application number: PCT/DK1993/000050
Authority: WO
Inventors: Karl Johan Klitgaard Frandsen
Original assignee: K.F. Industri A/S
Priority date: 1992-02-17
Filing date: 1993-02-12
Publication date: 1993-08-19
Also published as: DK20392A; AU3493393A; DK20392D0

Abstract

A portable high-pressure cleaner comprising a pump part (4) with a pumping chamber (24) and valve and displacement means (14, 22, 26) between a low-pressure part (10, 32) where the pump medium, particularly water, is supplied, and a high-pressure part (12) with a discharge connection to an auxiliary tool, for instance a jet pipe, and an internal combustion engine for the pump part (4), said valve means comprise a spring affected pressure valve (26), and where the displacement means consist of a hollow, cylindrical pump piston (14), which is directly drive connected with an engine piston (20), which pump piston (14) is permanently connected to the low-pressure part (10, 32) via suction openings (65) to the cavity of the pump piston, as the valve means comprise a suction valve (22) positioned at an open front end of the pump piston, of which suction valve (22) a valve member (42) is connected with the pump piston (14) in such loosely displaceable manner that the valve member (42) only by inertia stress may close the front of the pump piston (14), when moving it towards the pumping chamber (24) and the pressure valve (26), and open the front of the pump piston (14), when moving it towards the low-pressure part (10), and where connected to the low-pressure part (10) a stiff water supply connection and an elastic element is present, which element consists of a piece of flexible tube or preferably of an elastic diaphragm (38) being mounted in a side flange (36). In a simple manner the possibility of optimum refilling by renewed pump movement of the piston is obtained.

Description

A portable high-pressure cleaner

The present invention relates to a portable high-pressure cleaner, in particular for hobby purposes, and of the type described in the introductory part of claim 1.

For leisure-time or hobby purposes it is known to produce lightweight and compact high-pressure cleaners. However, it is often a question of downward-dimensioned and equipmentwise simplified versions of high-pressure cleaners for professional use, that is to say that known high-pressure cleaners for hobby purposes normally also are encum¬ bered with the same disadvantages as high-pressure cleaners for professional use - including a relatively high price. Furthermore, known high-pressure cleaners of this type are relatively heavy units because they either include a conventional petrol engine or an electric motor. In the last-mentioned case in addition to connection to proper elec¬ tricity supply a special security system is required because of the connection to water supply.

The invention is more precisely related to a portable high-pressure cleaner, which is described in Danish Patent Application No 0724/90 and international application No.

PCT/DK91/00080 (WO91/14517), and the purpose of the invention is to provide a portable high-pressure cleaner of the type mentioned introductorily, and which by simple provisions may be given a better and more stable efficiency.

The high-pressure cleaner according to the invention is distinctive in that connected to the low-pressure part a stiff water supply connection and an elastic element is present, which element consists of a piece of flexible tube or preferably of an elastic diaphragm being mounted in a side flange. In a simple manner the possibility of optimum refilling by renewed pump movement of the piston is obtained. The elastic element is with reference to capacity such adapted, that it exactly gives the necessary filling supplement (0.3 to 0.6 ml); and in respect to the fact that only about 1.2 ml is sucked in per pump stroke, it concerns a considerable filling supplement, which is delivered by the elastic element. The elastic element consists as mentioned preferably of a diaphragm of elastic material, which expediently is stretched tranversely over the side flange by means of a screw with a concave cavity towards a suction chamber, which cavity permits the diaphragm to be stretched outwards during the return stroke (suction stroke) of the hollow pump piston, and swing inwards during the pump stroke.

In the following the invention is described in more detail with reference to the drawing, in which:

Fig. 1 shows a side view - partly in section - of an embodiment for a high-pressure cleaner according to the invention,

Fig. 2 shows a view - partly in section - of the high-pressure cleaner shown in Fig. 1 - seen from above,

Fig. 3 shows an end view - parly in section - seen from the section line m-E in Fig. 1, and

Fig. 4 shows a side sectional view of the preferred embodiment for a pump part to the high-pressure cleaner shown in Fig. 1 - 3 according to the invention.

The high-pressure cleaner shown in Figs. 1 - 3 comprises a pump part 4 - shown in a preferred embodiment in Fig. 4 - a crank mechanism 6 and a drive engine in form of a petrol engine 8. The pump part 4 comprises a low-pressure side or part 10 and a high- pressure side or part 12 and a between these placed hollow, tube-shaped pump piston 14, which via a crosshead 16, connecting rods 18 and a crank mechanism 6 is directly drive connected with an engine piston 20 of the petrol engine 8. The pump part 4 also comprises a suction valve 22, a pumping chamber 24, a pressure valve 26 and a discharge nozzle for connection of a jet pipe. The pump piston 14 is opposite the suction valve 22 connected with a cylindrical connecting part 30, being connected with the cross head 16 opposite the pump piston 14. A rearmost part of the pump piston 14 and the connecting part 30 stretching on the low-pressure side 10 through a suction chamber 32, to which chamber water at water- works pressure (2 to 8 bar) is supplied through a ball valve 34 adapted to open by means of an activation lever 36, via a pivot arm 38 connected with a velocity regulator 40 (speeder) for the petrol engine 8. When the latter for instance is running at idle speed (equivalent to about 3,000 rpm) the ball valve 34 is closed so that no water is supplied to the pump part 4, which - at least shortly - should stand to operate without water supply.

The valve flange 34 is connected to the water supply by means of a not shown stiff pipe connection, (which previosly consisted of a flexible tube). To compensate for this stiff and non-elastic connection, the suction chamber 32 opposite the valve flange 34 is provided with a side flange 36, in which an elastic diaphragm 38 is stretched out, which diaphragm is secured by means of a large, short screw 40, which is provided with a concave cavity 42 towards die suction chamber 32, which cavity permitting the dia¬ phragm 38 to be pressed inwards die cavity 42.

During the return stroke (the suction stroke) of the hollow pump piston 14 some water is displaced behind, and the elastic diaphragm 38 is intended to assist (in stead of the earlier flexible tube connection) in obtaining optimum re-filling of the suction chamber, when the piston is again moved forward.

Claims

C L A I M S

1. A portable high-pressure cleaner comprising a pump part (4) with a pumping chamber (24) and valve and displacement means (14, 22, 26) between a low-pressure part (10, 32) where the pump medium, particularly water, is supplied, and a high- pressure part (12) with a discharge connection to a auxiliary tool, in particular a jet pipe, and an internal combustion engine for the pump part (4), said valve means comprise a spring affected pressure valve (26), and where the displacement means consist of a hollow, cylindrical pump piston (14), which is directly drive connected with an engine piston (20), which pump piston (14) is permanently connected to d e low- pressure part (10, 32) via suction openings (65) to the cavity of d e pump piston, as the valve means comprise a suction valve (22) positioned at an open front end of the pump piston, of which suction valve (22) a valve member (42) is connected with the pump piston (14) in such loosely displaceable manner, that the valve member (42) only by inertia stress may close the front of the pump piston (14), when moving it towards the pumping chamber (24) and die pressure valve (26), and open the front of the pump piston (14), when moving it towards die low-pressure part (10) c h a r a c t e r i z e d in that connected to the low-pressure part (10) a stiff water supply connection and an elastic element is present, which element consists of a piece of flexible tube or preferab¬ ly of an elastic diaphragm (38) being mounted in a side flange (36).

2. A high-pressure cleaner according to claim 1, c h a r a c t e r i z e d in that said diaphragm is stretched tranversely over the side flange (36) by means of a screw (40) with a concave cavity (42) towards a suction chamber, which cavity permits the dia¬ phragm (38) to be stretched outwards during the return stroke (suction stroke) of the hollow pump piston.