A PORTABLE HIGH-PRESSURE CLEANER

Abstract: By a portable high-pressure cleaner (66) comprising a pump part (4) with a pumping chamber (24) and belonging valve and displacement means (14, 22, 26) between a low-pressure part (10, 32) where the pumped medium, by way of example water, is supplied, and a high-pressure part (12) with a discharge connection to a utility tool, by way of example a jet pipe, and an engine, preferably an internal combustion engine, the displacement means comprise a hollow, cylindrical pump piston (14) which preferably via a crosshead (16), connecting rods (18) and a crank (6) is drive connected directly with an engine piston (20), and which is permanently connected to the low-pressure part (10, 32) via intake openings (65) to the cavity of the pump piston, and an intake valve (22) positioned at an open front end of the pump piston, said intake valve being adapted to close the open front end of the pump piston (14) by forward movement of said pump piston towards a pressure valve (26) and the pumping chamber (24), and to open the front end of the pump piston (14) by rearward movement of said pump piston (14) towards the low-pressure part (10, 32).

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 is known to produc lightweight and compact high-pressure cleaners. However, i is often a question of downward-dimensioned and equipment wise versions of high-pressure cleaners for professiona use, that is to say that known high-pressure cleaners fo hobby-purposes normally also are encumbered with the sam disadvantages as high-pressure cleaners for professiona use - including a relatively high price. Furthermore, know high-pressure cleaners of this type are relatively heav units because they either include a conventional petrol en gine or an electric motor. In the last-mentioned case i addition to connection to proper electricity supply a spe cial security system is required because of the connectio to a water supply. The invention has for its purpose to provide an improve high-pressure cleaner of the type mentioned initially, b means of which a significant use-wise flexibility and in creased reliability are achieved - even at reduced manufac turing costs. The high-pressure cleaner according to the invention is di stinctive in that the displacement means comprise a hollow, cylindrical pump piston which via a crosshead, connectin rods and a crank is drive connected directly with an engin piston arranged parallel to the pump piston which is per manently connected to the low-pressure part via intak openings to the cavity of the pump piston, that the valv means comprise an intake valve positioned at an open fron end of the pump piston, and that a valve member of said in take valve is connected to the pump piston in such loosely displaceable manner that the valve member by inertia stress is removed from the open front end, when the pump piston is moved rapidly towards the low-pressure part, and displaced towards the open end when the pump piston is moved rapidly in the opposite direction. In this manner is obtained a strongly improved high-pressure which in conse¬ quence of the simple and compact construction in particular is suited as a portable cleaning apparatus which despite the modest size has a very significant cleaning capacity. And furthermore, by means of simple constructional provi¬ sions is obtained an intake valve build together with the hollow pump piston which without valve spring means may operate with a relatively high on/off frequency (50 - 160 opening/closing movements per second) . Advantageously, the pump piston with the open end may be provided as a thin-walled tuBfe piece, preferably made of stainless steel. That is to say that the actual pump piston is light and sturdy. In order to obtain a simplified and sturdy construction the high-pressure cleaner according to the invention is such provided that the pump piston opposite the open front end has a concentric connecting part with small diameter, said connecting part being provided with a central, through- going bore provided with an internal thread, said threaded bore serves the purpose of fixing the pump piston to a crosshead and to a guiding pin stretching centrally through the pump piston, on which guiding pin said valve member for the intake valve is journaled. Expediently the high-pressure cleaner according to the in¬ vention is such provided that the pump piston at a prefer- able inclined, cylindrical reducing piece to the connecting part is provided with a number of intake channels the axe- ses of which stretching rearwards in an acute angle in re¬ lation to the centre-axis of the pump piston. Hereby in a simple manner is achieved an extra easy supply of water from the low-pressure part into the hollow pump piston both during the forward pumping movement and during the rearward intake movement of the pump piston. In order to obtain a larger cleaning capacity and to uti¬ lize a sort of differential effect in the low-pressure part or on the intake-side of the pump piston the high-pressure cleaner according to the invention is such provided that a rearmost part of said hollow pump piston, said inclined, cylindrical reducing piece and the connecting part of the pump piston are stretching through the low-pressure part in the form of an intake chamber. By simple provisions the said differential effect is hereby obtained on the lowpres- sure side such that the supply of water into the hollow pump piston from the intake chamber is optimal during the pump stroke as well as during the intake stroke. In the following the invention is described in more detail with reference to the drawing, in which:- Fig. 1 is a view - partly in section - of an embodiment of a high-pressure cleaner according to the invention - as seen from above, Fig. 2 a side view - partly in section - of the high-pres¬ sure cleaner shown in Fig. 1, Fig. 3 an enlarged sectional view of the pump part of the high-pressure cleaner shown in Fig. 1, Fig. 4 an enlarged sectional view of the pump part of the high-pressure cleaner shown in Fig. 2, Fig. 5 a side view - partly in section - of a preferred em¬ bodiment of a high-pressure cleaner according to the inven¬ tion, Fig. 6 a view - partly in section - of the high-pressure cleaner shown in Fig. 5 - as seen from above, Fig. 7 an end view - partly in section - as seen from the section line VII-VII in Fig. 5. Fig. 8 a side view - mainly in section - of an embodiment of a pump part of the high-pressure cleaner according to the invention shown in Figs. 5 - 7, while, Fig. 9 is a sectional view of a pump piston for the pump part shown in Fig. 8 for a high-pressure cleaner according to the invention. The high-pressure cleaner 2 shown in Figs, l and 2 com- prises a pump part 4 shown in Fig. 3 and in part in Fig. 4, a crank mechanism 6 and a motor .in the form of a petrol en¬ gine 8. The pump part 4 comprises a low-pressure side or part 10 and a high-pressure side or part 12 and a hollow, tubular pump piston 14 placed in between, which via a crosshead 16, connecting rods 18 and the crank mechanism 6 is drive connected directly with a drive piston 20 of the petrol engine 8. Furthermore, the pump part comprises an intake valve 22, a pumping chamber 24, a pressure valve 26 and a discharge stub 28 for the connection of a jet pipe. The pump piston 14 is opposite the intake valve 22 con¬ nected with a cylindrical connecting part 30 being con¬ nected with the crosshead 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 an intake chamber 32 to which water at waterworks pressure (2 - 8 bar) is supplied through a ball valve 34 adapted to open by means of an activation rod 36, via a pivot arm 38 connected with a velocity regulator 40 (speeder) for the petrol en¬ gine 8. When the latter by way of example is running at idle speed (corresponding to about 3.000 rpm) the ball valve 34 is closed such that no water is supplied to the pump part 4 which at least shortly - should stand to ope¬ rate without water supply. The intake valve 22 comprises a valve member 42 which at the open front end of the pump piston 14 is loosely, dis- placeable journaled in a valve holder 44 secured to the pump piston 14, that is that the valve holder 44 is dis¬ placed forwards and backwards together with the pump piston 14. The valve member 42 is guided in the valve holder 44 by means of a stem,portion 46 facing forward and which in a way together with the valve member 42 constitutes the pro¬ per displacement surface of the pump piston 14. When the pump piston 14 including the valve holder 44 during opera- tion is displaced rapidly forwards and backwards the valve member 42 will among other things as a consequence of the inertia stress automatically be pressed towards the ope front end of the pump piston 14 when the latter during th pumping stroke - is forwardly displaced, and be remove from the open front end of the pump piston 14 when the lat ter during the intake stroke - is rearwardly displaced. Du ring the pumping stroke the counterpressure in the pumpin chamber of course will also actuate the intake valve 22 t close by pressing the valve member 42 towards the ope front end of the pump piston 14. The pump piston 14 operates in a pump cylinder 48, whic at the low-pressure side 10 of the pump part is closed b means of a stuffing box 50 through which the pump piston 1 also stretches. Opposite the stuffing box 50 the pumpin chamber 24 is provided in the form of a ring-shaped membe which like the other parts of the pump part 4 is secured in a surrounding plastic mantle 52. The latter may consist of two parts or be provided by casting in of the several parts of the pump part, as the plastic mantle 52 constitutes a foremost handle.for the high-pressure cleaner 2. Opposite the pump piston 14 the pumping chamber 24 forms an engagement surface for the pressure valve 26 as a valve member or valve disk 54 by means of a centre spindle 56 is displaceably journaled in a valve housing 58 which com¬ prises a ring-shaped cavity 60 around a central guide bushing 62 for the centre spindle 56. The ring-shaped cavi¬ ty 60 constitutes a holder for a compression spring 64 en¬ suring the pressing of the valve member 54 against the front side edge of the pumping chamber 24. The tubular pump piston 14 is at the rear end, that is to say at the junction to the connecting part 30 provided with radial intake channels 65 which from the intake chamber 32 see to the supply of water from the low-pressure part 10 into the hollow pump piston 14. In front of the intake channels 65 the pump piston 14 has enlarged diameter com¬ pared to that of the connecting part 30, that is to say that the pump piston 14 and the connecting part 30 at the lowpressure side 10 constitutes a sort of differential pi¬ ston reciprocating in the intake chamber 32 and which re¬ sults in supply of water from the intake chamber 32 into the hollow pump piston 14 during the forward pumping stroke as well as during the rearward intake stroke of the pump piston 14. By the preferred embodiment of the high-pressure cleaner 66 shown in Figs. 5 - 7 the same references have been used for the parts which are recovered by the high-pressure cleaner 2 cfr. Figs. 1 - 4. Furthermore, the high-pressure cleaner 66 comprises a petrol tank surrounding the pump part 4, a carburettor operated by means of the speeder 40 placed in a handle 72 which as indicated by arrows 74 in addition is used as supply channel for cooling air to the motor, a flywheei 76 with belonging ignition-system 78. The pump part 4 of the high-pressure cleaner 66 is shown in more detail in Fig. 8 where among other things it may be seen that the pumping chamber 24 is provided in a ring- shaped part 80, which in addition comprises an escape valve mechanism 82 as the ring-shaped part 80 at the front end is held in place against a combined holder part and valve hou¬ sing part for the pressure valve 26 by means of a disc spring 84 such that the part 80 is allowed to be displaced in forward direction in case of a too high pressure behind the pressure valve 26, by way of example if a connected jet pipe is blocked so that the excess-pressure may be drained off via a lower radial opening 86. By the high-pressure cleaner 66 the intake valve 22 is ar- ranged in a different way than that of the high-pressure cleaner 2 where the valve member 22 is displaceably jour¬ naled in a valve housing 44. Instead a valve member 88 at the open front end of the hollow pump piston 14 is displa¬ ceably journaled on a valve pin 90 stretching centrally through the hollow pump piston 14 and secured to a support bushing 92 being secured inside a central bore 94 of the connecting part 30. The valve member 88 cooperates with a head part 96 of the valve pin 90 in such a way that the valve member 88 is allowed to be removed very little from the open front end of the pump piston 14 when the latter during the intake stroke is displaced rearwards etc. The high-pressure cleaner 66 comprises like the high-pressure cleaner 2 a water supply 98 which is partly surrounded by a sound absorber 100.

Claims: C L A I M S : 1. A portable high-pressure cleaner comprising a pump part with a pumping chamber and belonging valve and displacement means between a low-pressure part where the pumped medium, by way of example water, is supplied, and a high-pressure part with a discharge connection to a utility tool, by way of example a jet pipe, and an engine, preferably an inter¬ nal combustion engine, c h a r a c t e r i z e d in that the displacement means comprise a hollow, cylindrical pump piston which via a crosshead, connecting rods and a crank is drive connected directly with an engine piston arranged parallel to the pump piston which is permanently connected to the low-pressure part via intake openings to the cavity of the pump piston, that the valve means comprise an intake valve positioned at an open front end of the pump piston, and that a valve member of said intake valve is connected to the pump piston in such loos'ely displaceable manner that the valve member by inertia stress is removed from the open front end, when the pump piston is moved rapidly towards the low-pressure part, and displaced towards the open end when the pump piston is moved rapidly in the opposite di¬ rection. 2. A portable high-pressure cleaner according to claim 1, c h a r a c t e r i z e d in that the pump piston with the open end is provided as a thin-walled tube piece, preferab¬ ly made of stainless steel. 3. A portable high-pressure cleaner according to claims 1 and 2, c h a r a c t e r i z e d in that the pump piston opposite the open front end has a concentric connecting part with small diameter, said connecting part being provi¬ ded with a central, through-going bore provided with an in¬ ternal thread, said threaded bore serves the purpose of fixing the pump piston to a crosshead and to a guiding pin stretching centrally through the pump piston, on which gui¬ ding pin said valve member for the intake valve is jour¬ naled. 4. A portable high-pressure cleaner according to claims 1 - 3, c h a r a c t e r i z e d in that the pump piston at a preferable inclined, cylindrical reducing piece to the con¬ necting part is provided with a number of intake channels the axeses of which stretching rearwards in an acute angle in relation to the centre-axis of the pump piston. 5. A portable high-pressure cleaner according to claims 1 - 4, c h a r a c t e r i z e d in that a rearmost part of said hollow pump piston, said inclined, cylindrical redu- cing piece and the connecting part of the pump piston are stretching through the low-pressure part in the form of an intake chamber.

Inventors: FRANDSEN KARL JOHAN KLITGAARD, FRANDSEN, KARL, JOHAN, KLITGAARD
Applicants: K F IND AS, K.F. INDUSTRI A/S
Application year: 1991
Main classification: B08B3
IPC codes: B08B3, F04B53