Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/02—Cleaning by the force of jets or sprays
  • B08B3/026—Cleaning by making use of hand-held spray guns; Fluid preparations therefor

Definitions

• the present invention relates to a high-pressure cleaner of the kind comprising a) an inlet for liquid at a relatively low pressure, b) a high-pressure pump, the suction side of which is connected to the liquid inlet and the pressure side of which is connected to c) the drive-nozzle inlet in an injector, the outlet of which is connected to a cleaning gun, and d) an automatic control unit comprising dl) a cylinder chamber in which a spring-loaded piston is sealingly and slidingly supported and hence divides the cylinder chamber into two part- chambers of which the first is connected to the suction inlet of the injector and the second is connected to the pressure side (8) of the pump, d2) a pressure-release chamber separated from the second chamber by a partition with a through-going opening, and d3) a piston rod secured to the piston and from the latter extending partly through the first chamber and sealingly and slidingly through an opening in the external wall of the first chamber for engagement with the operating member of a switch inserted in the power supply circuit of the
• the spring- biasing of the piston is provided by at least two heli ⁇ cal compression springs placed in the second chamber, of which at least one spring acts upon the piston solely along a part of the total path of movement of the piston.
• the pressure- release valve is constituted by a) the opening extending through the partition and having a cylindrical surface, and b) a cylindrical valve member secured to or integral with the piston rod and co-operating slidingly and seal ⁇ ingly with the cylindrical surface in the opening, said valve member comprising a pressure-re e channel adapted to connect the second chair.-er with t .ressure-release chamber solely in said second position ⁇ . Figure 3) .
• the sealing function between the cylindrical wall in the opening and said valve member is effected by an O-ring situated in a circumferential groove in the cylindrical surface.
• Figure l is an overall view showing diagrammatically the parts of a high-pressure cleaner relevant to the present invention including the automatic control unit, and Figures 2-4 at a larger scale show the automatic control unit of Figure 1 in three different states of operation.
• a supply conduit 1 adapted to be connected to a suit- able source of cleaning liquid, normally water, such as a water-mains connection, a high-pressure pump assembly 2 comprising
• a cleaning gun 11 adapted to eject a jet of clean ⁇ ing liquid at a high velocity.
• the parts 1-11 men- tioned above function in a manner known in principle in causing a jet of liquid to be ejected from the cleaning gun 11, this gun for control purposes having a manually operable valve (not shown) capable of interrupting the connection between the second high-pressure conduit 10 and the gun's nozzle.
• the high-pressure cleaner diagrammatically shown in Figure 1 also comprises an automatic control unit 12, connected hydraulically through a first pressure-release conduit 13 to the supply conduit 1, through a second pressure-release conduit 14 to the first high-pressure conduit 8, and - through a control-pressure conduit 15 to the suction inlet of the injector 9.
• an automatic control unit 12 connected hydraulically through a first pressure-release conduit 13 to the supply conduit 1, through a second pressure-release conduit 14 to the first high-pressure conduit 8, and - through a control-pressure conduit 15 to the suction inlet of the injector 9.
• the automatic control unit 12 is connected through an ON/OFF switch 16 connected in a manner not shown to the supply circuit of the drive motor 6.
• the automatic control unit 12 shown in Figures 1-4 com ⁇ prises a substantially cylindrical housing 17 that is hollow and permanently closed at one of its ends, while the opposite end is closed by a gland 18 co-operating with a stationary transverse wall 19 to act as a guide for a piston rod 20, to which a piston 21 is secured.
• the piston 21 divides the space between the gland 18 and the transverse wall 19 to form two chambers, i.e. a first chamber 22 between the gland 18 and the piston 21 and a second chamber 23 between the piston 21 and the transverse wall 19.
• the piston rod 21 comprises an extension 24, the free end of which is capable of abutting against the operating member 25 of the ON/OFF switch 16 already referred to above.
• the contacts of the switch 16 are so arranged, that electrical power may be supplied to the drive motor 6 in the pump assembly 2 when the operating member 25 is depressed as indicated in Figure 2.
• the space within the housing 17 to the left of the trans ⁇ verse wall 19 constitutes a pressure-release chamber 26 adapted to communicate with the second chamber 23 when the piston rod 21 is in the position shown in Figure 3, in which a pressure-release channel 27 formed in the piston rod 21 connects the two chambers with each other.
• the second chamber 23 accommodates two helical compression springs, i.e. a first spring 28 constantly urging the piston 21 towards the gland 18, and a second spring 29 also urging the piston 21 towards the gland 18, but not further than to the position shown in Figure 3, so that only the first spring 28 acts on the piston 21 in the position shown in Figures 2 and 4.
• a stop abutment 30 limits the extent of movement of the piston 21 towards the right in the drawing, and the ex ⁇ tension 24 of the piston rod 20 extending through the gland 18 is preferably so dimensioned that under no cir ⁇ cumstances will the operating member 25 be depressed beyond its normal contact-connecting position.
• the first chamber 22 is connected to the suction inlet in the injector 9 through the control-pressure conduit 15, the second chamber 23 is connected to the first high-pressure conduit, i.e. the pressure side of the pump, through the second pressure- release conduit 14, while the pressure-release chamber 26 is connected to the supply conduit 1 through the first pressure-release conduit 13.
• the pump pressure P2 is higher than the control pressure P3 in the control-pressure conduit between the suction inlet of the injector 9 and the first chamber 22 in the control unit 12.
• the control pressure P3 is - due to the intense flow of liquid from the pump assembly 2 to the cleaning gun 11 through the injector 9 - so low that the piston 21 is urged towards the gland 18 against the stop abutment 30, thus holding the switch 16 in the contact-connecting position enabling electrical power to be supplied to the drive motor 6.
• an auxiliary start ⁇ ing contact may be necessary to supply elec- trical energy to the drive motor 6 until such flow has been established.
• Such a contact could be a "short-make" contact operated by the trigger in the cleaning gun 11.

Landscapes

• Cleaning By Liquid Or Steam (AREA)
• Reciprocating Pumps (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=8154942

Family Applications (1)

Country Status (5)

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Family Cites Families (5)

• 1994
  • 1994-11-07 EP EP95902064A patent/EP0790866B1/de not_active Expired - Lifetime
  • 1994-11-07 DE DE69412868T patent/DE69412868T2/de not_active Expired - Fee Related
  • 1994-11-07 AU AU11060/95A patent/AU1106095A/en not_active Abandoned
  • 1994-11-07 WO PCT/DK1994/000418 patent/WO1996014171A1/en active IP Right Grant
  • 1994-11-07 DK DK95902064T patent/DK0790866T3/da active

Non-Patent Citations (1)

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