A liquid-ejection device for a high-pressure cleaning apparatus

Abstract

 A liquid ejection device for a pressure-cleaning apparatus, comprising a housing (2) with means (4) for receiving a liquid supply tube (5), a tubular body (7) having a multiple of axially orientated flow channels (16,17), a first end inserted in concentric connecting means in the housing for connecting the tubular body (7), and a second end with an ejection nozzle (8), and means (6) for regulation of the pressure of the liquid spray ejected through the tubular body (7), wherein said regulation means (6) includes a valve member (10) having a threaded portion (10') by which it is rotatably mounted, and a flow passage (14) for feeding one or more of the flow channels of the tubular body with pressurised liquid. By the invention, a liquid ejection device is provided with a pressure regulation that may be adjusted to any pressure between a minimum and a maximum pressure due to the threaded mounting of the valve member.

Description

[0001] The present invention relates to a liquid ejection device for a pressure-cleaning apparatus, comprising a housing with means for receiving a liquid supply tube, a tubular body having a multiple of axially orientated flow channels, a first end inserted in connecting means in the housing for connecting the tubular body, and a second end with an ejection nozzle, and means for regulation of the pressure of the liquid spray ejected through the tubular body.

[0002] From US 6,016,975 a water ejection device is known wherein the water is supplied at a certain pressure and ejected with either a high pressure or a low pressure. The pressure regulation mechanism consists of a tubular member on the outer side of the cylindrical body that is slidable in the axial direction between an open and a closed position. The drawback of this washing gun is that only two pressure outputs may be achieved. Moreover, the pressure regulation may be difficult to operate since the pressure changing mechanism is provided at the nozzle or near the ejection nozzle on the cylindrical body, usually referred to as the lance.

[0003] Other similar washing guns or liquid ejection devices are known from US 4,886,213 and EP-A-0 501 164, but do all accommodate similar disadvantages and limitations in use.

[0004] For this reason amongst other reasons, it is the object of the present invention to provide a liquid ejection device that allows for more flexibility in cleaning operations and that is easier and simpler to operate.

[0005] These objections are achieved by a liquid ejection device of the initially mentioned kind, wherein the regulation means includes a valve member with a threaded portion by which it is rotatably mounted, and a flow passage for feeding one or more of the flow channels of the tubular body with pressurised liquid.

[0006] By the invention, a liquid ejection device is provided with a pressure regulation that may be adjusted to any pressure between a minimum and a maximum pressure due to the threaded mounting of the valve member. The threaded mounting is designed in such a way that it is ensured that the valve member is retained in the predetermined position set by the operator and is not moved by the pressurised flow in the channels. This could be achieved by providing the threaded portion with a self-locking thread pitch or at least a sufficiently fine screw pitch. By altering the position of the valve member, the pressurised flow from the flow passage is fed into one or more of the flow channels depending on the amount of pressure desired, i.e. the volume of the "active" flow channels. If maximum pressure is chosen only one of the flow channels are active, and if any pressure less than maximum is desired, the opening for liquid flow into the other flow channel or channels is present and increased in size, so that the smaller pressure desired, the larger the opening is.

[0007] In the preferred embodiment of the invention, the valve member is rotatably mounted in the housing. Hereby, a particular simple operation of the pressure control may be achieved since the pressure regulation is provided in the handle of the liquid spraying device. This means that the operator of the device can also operate during use in a simple manner.

[0008] Preferably, the valve member is provided in the housing in such a way that axial distance between the valve member and the first end is adjustable. Hereby, the infinitely variable pressure regulation is simple in design and involves relatively few parts. In this embodiment, the valve member is preferably provided with a valve seat flange that corresponds to the first end of the tubular body in such a way that at least one of the flow channels are blocked when the valve seat flange abuts the first end.

[0009] Preferably, the valve member is provided with a concentric disk portion that partly extends outside the housing. Hereby, the pressure may be regulated by rotating the disk in a clockwise or anti-clockwise direction in order to increase or decrease the pressure. The disk is positioned in the housing near the hand of the operator, so that the pressure regulation easily may be carried out by the operator during use.

[0010] In a preferred embodiment, index means are provided between the valve member and the housing. Preferably, the index means include a spring-loaded ball that co-operates with annularly disposed cavities on the disk portion of the valve member. Hereby, the operator will be able to sense a response to the adjustments due to audible clicks as the disk is rotated.

[0011] In the preferred embodiment of the invention, the tubular body comprises an inner tube and an outer tube, said tubes being aligned substantially concentric and defining a central flow channel and an annular second flow channel. By this double chambered, tubular body, the device is provided with a robust lance that is comfortable and handy to use. Moreover, by having a multiple of flow channels whilst maintaining a cylindrical outer shape the operator can easier get a firm grip on the tube, just as an adjustable support handle is easy to fit onto the cylindrical, tubular body.

[0012] Preferably, the central flow channel is substantially aligned with the feeding flow passage of the valve member. Hereby, the flow passage of the valve member is constantly in flow communication with the central flow channel of the tubular body, irrespective of the position of the valve member.

[0013] In the double tube, the second flow passage is only open when the device is adjusted in such a way that a pressure less than maximum pressure is to be ejected from the nozzle of the device. Hereby a particular simple and reliable cooperation between the tubular body and the valve member is achieved in order to provide the pressure regulation.

[0014] The invention is described detail below with reference to the accompanying drawings, in which

Fig. 1

is a schematic, perspective view of a liquid ejection device according to the invention,

fig. 2

is a detailed cross-section side view of the device adjusted to maximum pressure delivery, and

fig. 3

is the same in the minimum position.

[0015] In fig. 1, a liquid ejection device is shown. It comprises a housing 2 or main body with a trigger 3 for operating the device. The housing 2 has a connecting means 4 for receiving and connecting a liquid supply pipe 5. The supplied liquid is supplied at a certain pressure from a base station (not shown). The liquid may be water, a cleaning agent, or a mixture thereof. In the housing 2, pressure regulating means 6 are provided. The liquid flows through the housing 2 via the pressure regulating means 6 and into a tubular body 7, often referred to as a lance. The tubular body 7 is provided with a first end adapted to be releasably connected to the housing 2. The liquid is ejected from a spraying nozzle 8 at the second end of the tubular body.

[0016] The tubular body 7 may preferably be provided with a handle 9 for holding and directing the direction of liquid spray from the nozzle 8. In the preferred embodiment, the tubular body 7 is cylindrical in shape. Hereby, it is possible to provide an adjustable handle 9 for fitting the device according to the operator's preferences. The handle 9 may be made with means for releasably fastening it around the tubular body 7. Hereby, the handle 9 may be pivoted from one side of the device to the other, thereby setting up the device for left-handed or right-handed operator. Moreover, the handle 9 may be shifted in the axial direction.

[0017] In figures 2 and 3, the pressure regulating means 6 inside the housing 2 is shown in detail. In fig. 2, the pressure regulating means 6 are shown in the maximum pressure position and in fig. 3 in the minimum pressure position. The pressure regulating means includes a valve member 10 that is rotatably mounted between a first and a second housing element 11, 12. The valve member 10 comprises a cylindrical, threaded portion 10' that is rotatably mounted in the housing element 11 via a corresponding thread 11' in the housing element 11. The valve member 10 has a cylindrical portion 13 encompassing a corresponding portion of the second housing element 12 in such a way that the valve member may slide in the axial direction on the second housing element 12. The first housing element 11 is - at the end opposite the end accommodating the valve member 10 - designed to receive the tubular body 7, which is releasably connected to the housing 2.

[0018] The valve member 10 is provided with a central flow passage 14 through which the pressurised liquid flow from the flow passage 15 in the housing is directed towards the tubular body 7, see figs. 2 and 3.

[0019] A main valve 29 is provided in the flow passage 15 of the housing 2. This main valve 29 is operated by the trigger 3.

[0020] The tubular body 7 includes two concentric cylindrical tubes 18, 19 defining a central flow channel 16 and an annular outer flow channel 17. The central flow channel 16 is axially aligned with the valve flow passage 14.

[0021] The valve member 10 is provided with a disk 20 that partly extends out of the housing 2 so that the operator of the device can rotate the valve member 10 in order to regulate the pressure of the liquid spray. Retention means 21, 22, 23 are provided between the first housing element 11 and the disk 20. The retention means include a spring-loaded ball 22 that is biased towards the disk 20 by a biasing member 21, such as a spring or the like. On the disk, a number of annularly arranged dimples 23 are provided. The dimples 23 receive the outermost portion of the ball 22 whereby the disk 20 is provided with a certain amount of resistance against being rotated. Hereby, the valve member 10 is ensured against being forced out of the determined position corresponding to the desired pressure set by the operator.

[0022] The end of the valve member 10 is formed as a valve seat 24 with a shape that corresponds to the end flange 25 of the first end of the tubular body 7. When the valve member 10 is rotated to its forward position, as shown in fig. 2, the valve seat 24 abuts the end flange 25 of the tubular body 7 so that the pressurised liquid flow is exclusively directed from the flow passage 14 of the valve member 10 into the central flow channel 16 of the tubular body 7. This results in a high-pressure output at the nozzle 8.

[0023] As the valve member 10 is screwed backwards (relative to the direction of the liquid flow), a gap between the valve seat 24 and the end flange 25 emerges (see fig. 3). As the gap increases, the pressure output at the nozzle 8 drops since a ever larger portion of the liquid flows is diverted into the second flow channel 17 resulting in an increase in volume for the flow through the tubular body 7 and as a consequence a drop in pressure compared to the input pressure from the supply pipe 5.

[0024] As shown in figs. 2 and 3, the tubular body 7 are assembled at the end by an end piece 26 holding the central tube 18 inside the outer tube 19. The end piece 26 has a central bore 28 through which access is provided to the first flow channel 16 and a number of openings 27 through which access to the second flow channel 17 is provided.

[0025] The invention is described with reference to the above-described embodiment, but it is understood that other embodiments and equivalent solutions may be provided without departing from the scope of the invention that is defined in the accompanying claims.

Claims

1. A liquid ejection device for a pressure-cleaning apparatus, comprising

a housing with means for receiving a liquid supply tube,

a tubular body having a multiple of axially orientated flow channels, a first end inserted in connecting means in the housing for connecting the tubular body, and a second end with an ejection nozzle, and

means for regulation of the pressure of the liquid spray ejected through the tubular body,

characterised by
said regulation means including

a valve member having

a threaded portion by which it is rotatably mounted, and

a flow passage for feeding one or more of the flow channels of the tubular body with pressurised liquid.

2. A liquid ejection device according to claim 1, wherein the valve member is rotatably mounted in the housing.

3. A liquid ejection device according to claim 2, wherein the valve member is provided in the housing in such a way that axial distance between the valve member and the first end is adjustable.

4. A liquid ejection device according to claim 3, wherein the valve member is provided with a valve seat flange that corresponds to the first end of the tubular body in such a way that at least one of the flow channels are blocked when the valve seat flange abuts the first end.

5. A liquid ejection device according to claim 1 to 4, wherein the valve member is provided with a concentric disk portion that partly extends outside the housing.

6. A liquid ejection device according to claim 1 to 5, wherein index means is provided between the valve member and the housing.

7. A liquid ejection device according to claim 6, wherein the index means include a spring-loaded ball that co-operates with annularly disposed cavities on the disk portion of the valve member.

8. A liquid ejection device according to any of the preceding claims, wherein the tubular body comprises an inner tube and an outer tube, said tubes being aligned substantially concentric and defining a central flow channel and an annular second flow channel.

9. A liquid ejection device according to claim 8, wherein the central flow channel is substantially aligned with the feeding flow passage of the valve member.

10. A liquid ejection device according to claim 8 or 9, wherein the second flow passage is only open when the device is adjusted in such a way that a pressure less than maximum pressure is to be ejected from the nozzle of the device.

Drawing