EP1383612A1

EP1383612A1 - Quick-release coupling for the lance of a high-pressure cleaning device

Info

Publication number: EP1383612A1
Application number: EP02742820A
Authority: EP
Inventors: Lasse Lind
Original assignee: Nilfisk Advance AS
Current assignee: Nilfisk AS
Priority date: 2001-05-03
Filing date: 2002-05-03
Publication date: 2004-01-28
Also published as: EP1254724A1; WO2002089997A1

Abstract

The present invention concerns a liquid ejection device for a pressure-cleaning apparatus, comprising a housing having means for receiving a liquid supply tube and directing the liquid flow to a tubular body including a first end of the tubular body being connectable to connecting means of the housing and a second end with an ejection nozzle, wherein the connecting means includes a tubular support element for receiving and supporting the tubular body, and that the support element is provided with locking means comprising a tubular sleeve, which is provided around and axially slidable on the tubular support element, and biasing means extending into co-operating receiving means in the tubular body for retaining the tubular body in a predetermined position, and that the locking means include operation means, which are operated by pressure, and movement transformation means transforming said generally radial pressure activation to an axial movement for operating the biasing means and sliding the tubular sleeve. By the intention, a liquid ejection device with quick release coupling of a tubular body to the housing is provided.

Description

QUICK-RELEASE COUPLING FOR THE LANCE OF A HIGH-PRESSURE CLEANING DEVICE

A liquid ejection device for a pressure-cleaning apparatus, comprising a housing having means for receiving a liquid supply tube and directing the liquid flow to a tubular body including a first end of the tubular body being connectable to connecting means of the housing and a second end with an ejection nozzle.

The US patent no. 6,016,975 discloses a washing gun, where the tubular body is permanently fastened to the housing. The tubular body is provided with two concentric flow channels with an axially operated dual pressure switching means at its first end. The first end is provided with a cylindrical bush with a flow passage that is permanently fastened to the hydrocleaner, i.e. the housing thereof.

The disadvantage of this device is that the tubular body cannot be changed without the use of special tools, if at all. The permanently fastening is provided by a threaded mounting, and if the tubular body is screwed out of the receiving thread in the housing, the risk of damaging the sealed engagement is eminent. In any case, the tubular body must be very accurately mounted on the housing in order to ensure a safe and reliable cleaning action by the liquid ejection device.

Moreover, it is not possible to change between one type of tubular body to another, e.g. between a long one and a short one or between tubular bodies with different ejection nozzles. Such changing possibilities are only known at the end of the tubular body, i.e. a change of nozzle type, see e.g. EP-A-1 043 080. With this type of nozzle coupling mechanism, it is quick to change the nozzle by removing a radial locking member that may be pulled out in a radial direction for releasing the nozzle. However, this coupling device is unsuitable for connecting the tubular body to the housing since the tubular body may carry a pressure regulation mechanism and must be held very firmly due to the long pointy tubular body and the high pressure of the flow inside the housing and the tubular body. It is therefore the object of the invention is to provide a releasable connection mechanism for a liquid ejection device for making it possible to change the tubular body in a quick and reliable manner without the use of any tools.

The object is achieved by a liquid ejection device of the initially mentioned kind, wherein the connecting means includes a tubular support element for receiving and supporting the tubular body, and that the support element is provided with locking means comprising a tubular sleeve, which is provided around and axially slidable on the tubular support element, and biasing means extending into co-operating receiving means in the tubular body for retaining the tubular body in a predetermined position, and that the locking means include operation means, which are operated by pressure, and movement transformation means transforming said generally radial pressure activation to an axial movement for operating the biasing means and sliding the tubular sleeve.

By the invention, a liquid ejection device with quick release coupling of a tubular body to the housing is provided. This makes it possible to change the type of tubular body or lance as it is often called, e.g. if it is demanded or if it is desirable with respect to the cleaning operation. Moreover, pressure regulating means may be provided in the housing whereby the tubular body may be designed in a more simple and more cost effective manner, just as the weight distribution of the entire device may be more comfortable seen from an operators point of view, as more weight may be moved to the housing and away from the tubular body. Also, by providing a pressure-activated operation of the locking means the release of the lance may be carried out in a quick and efficient manner by the person operating the ejection device.

Preferably, the operation means include an activation member, which is moveable in a radial direction and cooperating with movement transformation means including a radially outwardly projecting member fixedly mounted on the tubular sleeve. Hereby, a simple and robust release mechanism may be provided. In a preferred embodiment of the invention, the activation member is pivotably mounted in the housing at one end and provided with a roller member at the opposite end, said roller member cooperating with an inclined receiving surface of the radially outwardly projecting member on the tubular sleeve. Hereby, no further spring force than the biasing means of the tubular sleeve is needed to ensure that the activation member is returned to its rest position. The pressure force needed to operate the release mechanism may be determined by the spring force of the biasing means and by the angle of inclination of the surface with respect to the axial direction. By choosing a suitable shape of the surface and the diameter of the associated roller means, the required pressure force of the operating means is preferably obtainable by a thump of the operator.

Preferably, the activation member is arranged on the opposite side of the housing than the side of the housing where liquid flow regulation operation means are arranged. This means that the operator may change the lance, i.e. the tubular body, with a two-hand grip, i.e. with one hand on the tubular body and the other on the normal operating position around the housing.

Preferably, a spring is provided between the tubular support element and the tubular sleeve. By the spring, the sleeve is retained in a resting position where it is locking the biasing means so that the tubular body is retained in the housing.

In the preferred embodiment of the invention, the biasing means comprises a number of balls loosely fitted in apertures on the tubular support element, said balls having a diameter which is larger than the thickness of the tubular wall of the tubular support element. Hereby, a simple and efficient retention is achieved that is easy to release, in particular if the balls are mounted in the apertures with a spring loading.

In a preferred embodiment, the connecting means include an end surface of the first end of the tubular body that abuts an abutment surface on the housing. Hereby, the tubular body is mounted in the housing is a predetermined position whereby a predictable axial position is achieved. Moreover, the biasing means may be arranged in an annular ring on the tubular support element in a predetermined distance from the abutment surface of the connecting means. Similarly, the receiving means may consist of an annular recess on the tubular body in a distance from the end surface corresponding to the predetermined distance between the biasing means and the abutment surface. Hereby, a simple and efficient design of the connection means may be achieved. The predetermined outer shape of the tubular body may be provided on several different types of tubular bodies.

In order to achieve a close fitting, the outer shape of the first end of the tubular body preferably corresponds to the internal shape of the connection means of the housing.

In a preferred embodiment of the invention, the tubular body comprises an inner tube and an outer tube, said tubes being 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, doubled tubed 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.

Preferably, the central flow channel is substantially aligned with a feeding flow passage of a valve member of pressure regulation means provided in the housing. 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. The device according to this embodiment of the invention is also advantageous since the pressure regulation means is provided in the housing and that the dual channel tubular body is releasably connectable directly to the housing and the valve member of the pressure regulation means. 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.

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

fig. 1 is a perspective view of a liquid ejection device according to the invention, fig. 2 is a cross-section side view of the assembled device, fig. 3 is a cross-section side view of the housing, and fig. 4 is a cross-section side view of the tubular body of the device.

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.

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.

In fig. 2, the coupling between the housing 2 and the tubular body 7 is shown. The details of the connecting means of the housing 2 are shown separately in fig. 3 and the tubular body itself is shown in fig. 4.

The device shown in fig. 2, comprises a housing 2 with a trigger 3 for operating the main valve 29. A supply pipe 5 is connected to coupling means 4. The supplied liquid is pressurised and fed into a flow passage 15 and through the flow passage 14a and potentially also the flow passage 14b depending on the position of a valve member 10 of the pressure regulation means 6 that is accommodated in the housing 2. From the housing 2, the pressurised liquid is fed into the tubular body 7, which is connected to the housing 2.

The connecting means of the housing 2 includes a tubular extension 31 fixedly mounted in the first housing 2. Hereby, a cylindrical section is provided on the housing 2 wherein the outlets of the flow passages 14a, 14b are arranged. The tubular body 7 is inserted into the tubular extension 31 that both receives and supports the tubular body 7 once inserted. At the end of the tubular extension 31 , a tubular section 32 is provided having an increased internal diameter compared to the internal diameter of the tubular extension 31. The tubular section 32 is provided with a threaded portion to which a tubular support element 33 is mounted. The first end of the support element 33 substantially encompasses the end section of the tubular extension 31, which is provided with an inwardly protruding, annular, preferably conic receiving and aligning surface 40 for receiving and positioning the tubular body 7 by cooperating with a corresponding positioning surface 41 on the tubular body 7 (see figs. 2 and 4). At the other end, the tubular support element 33 is provided with a protrusion 34 for receiving a helical spring 35, which surrounds a portion of the tubular support element 33. At the inner surfaces of the tubular extension 31 and the tubular support element 33, sealing members 42 are provided in order to ensure a watertight coupling between the housing 2 and the tubular body 7.

Around the tubular support element 33, a tubular sleeve 38 is axially shiftable along the tubular support element 33. The sleeve 38 is provided with a cylindrical portion 39, which has a diameter that just fits around the tubular support element 33, whereas the rest of the sleeve 38 has a larger inner diameter than the outer diameter of the tubular support element 33. The end of the cylindrical portion 39 receives the other end of the helical spring 35 whereby the sleeve 38 is spring loaded and held in a resting position locking the biasing means 30.

On the outside of the sleeve 38 surrounding the cylindrical portion 39, an annular member 50 is fixedly mounted around the sleeve 38. This annular member 50 is provided with a protruding rim flange 51 having an inclined surface 52 at its side pointing away from the insertion area of the tubular body 7.

A push button 54 is pivotally mounted in the housing 2 by a pivot pin 55 at one end of the push button 54. At the other end, a roller 53 is mounted. This roller 53 is arranged in such a way that it engages the inclined surface 52, and when the push button 54 is pressed in a radial direction, i.e. downwards, the roller 53 pushed on the inclined surface 52, which in turn causes the sleeve 38 to be moved forward and thereby release locking means for the tubular body 7 from its locked position in the housing 2.

By pushing the sleeve 38 to a forward position, i.e. by compressing the spring 35, the biasing means 30 may be released so that the tubular body 7 may be removed or inserted into the receiving means of the housing 2.

The biasing means 30 include a ring of apertures 43 provided in the tubular support element 33. In the apertures 43, balls 36 with an at least slightly larger diameter than the thickness of the tubular wall of the support element 33 are provided. The balls 36 are loosely retained in the apertures 43, and could be spring-loaded in the apertures 43 is appropriate. The cylindrical portion 39 of the sleeve 38 blocks the apertures 43 when the sleeve 38 is in the resting position, as shown in fig. 2. This means that the balls 36 protrude into the inner space of the tubular support element 33 and into an annular groove 37 of the tubular body 7 and thereby prevents the tubular body 7 from being moved in the axial direction.

When the sleeve 38 is pushed forward, i.e. in the same direction as the flow direction, i.e. the axial direction, the balls 36 are allowed to protrude out of the apertures 43 tubular support element 33 instead of into the groove 37 of the tubular body 7, thereby releasing the tubular body from the housing 2.

The groove 37 and the annularly arranged balls 36 are positioned with the corresponding axial distances from the positioning surfaces 40 and 41 of the two parts 2, 7 to be joined. Hereby, an accurate coupling between the tubular body 7 and the housing 2 is achieved, wherein the first end of the tubular body 7, in particular the receiving surface 25 of the end piece 26 (see fig. 4) is accurately positioned relative to the receiving means of the housing 2.

The invention is described with reference to a first preferred embodiment, but it is realised that many variant may be provided, e.g. that the tubular body may be a double tube, as described above or any other type of tubular body with one or more flow channels. This and other embodiments and equivalents thereof may be provided without departing from the scope of the invention, as set forth in the accompanying claims.

Claims

PATENT CLAIMS:

1. A liquid ejection device for a pressure-cleaning apparatus, comprising a housing having means for receiving a liquid supply tube and directing the liquid flow to a tubular body including a first end of the tubular body being connectable to connecting means of the housing and a second end with an ejection nozzle, c h ar a c t e r i s e d i n th at the connecting means includes a tubular support element for receiving and supporting the tubular body, and that the support element is provided with locking means comprising a tubular sleeve, which is provided around and axially slidable on the tubular support element, and biasing means extending into co-operating receiving means in the tubular body for retaining the tubular body in a predetermined position, and that the locking means include operation means, which are operated by pressure, and movement transformation means transforming said generally radial pressure activation to an axial movement for operating the biasing means and sliding the tubular sleeve.

2. A liquid ejection device according to claim 1, wherein the operation means include an activation member, which is moveable in a radial direction and cooperating with movement transformation means including a radially outwardly projecting member fixedly mounted on the tubular sleeve.

3. A liquid ejection device according to claim 2, wherein the activation member is pivotably mounted in the housing at one end and provided with a roller member at the opposite end, said roller member cooperating with an inclined receiving surface of the radially outwardly projecting member on the tubular sleeve.

4. A liquid ejection device according to any of the claims 1 to 3, wherein the activation member is arranged on the opposite side of the housing than the side of the housing where liquid flow regulation operation means are arranged.

5. A liquid ejection device according to any of the preceding claims, wherein a spring is provided between the tubular support element and the tubular sleeve.

6. A liquid ejection device according to any of the preceding claims, wherein the biasing means comprises a number of balls loosely fitted in apertures on the tubular support element, said balls having a diameter which is larger than the thickness of the tubular wall of the tubular support element.

7. A liquid ejection device according to any of the preceding claims, wherein the connecting means include an end surface of the first end of the tubular body that abuts an abutment surface on the housing.

8. A liquid ejection device according to claim 7, wherein the biasing means are arranged in an annular ring on the tubular support element in a predetermined distance from the abutment surface of the connecting means.

9. A liquid ejection device according to claim 8, wherein the receiving means consists of an annular recess on the tubular body in a distance from the end surface corresponding to the predetermined distance between the biasing means and the abutment surface.

10. A liquid ejection device according to any of the preceding claims, wherein the outer shape of the first end of the tubular body corresponds to the internal shape of the connection means of the housing.

11. 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.

12. A liquid ejection device according to claim 11, wherein the central flow channel is substantially aligned with a feeding flow passage of a valve member of pressure regulation means provided in the housing.

13. A liquid ejection device according to claim 11 or 12, 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.