More specifically, the present invention relates to a spray device which can be used for cleaning by means of water and chemicals, for cleaning by means of air, for fire extinguishing, blasting, spray painting etc.

To simplify the specification, the present invention will be described based on the field of cleaning by using high-pressure sprayers, but it can of course be used for other applications in which a fluid flows though a valve.

High-pressure sprayers are used industrially, for in- stance, when cleaning equipment in the foodstuff indus- try, the chemical industry etc.

There are a number of different spray devices hav- ing a nozzle and a valve and intended for high-pressure sprayers with associated control means for opening and closing the flow through the spray nozzle. A common fea- ture of the different control means for the spray nozzles is that there must be a safety function which causes the flow to the spray nozzle to be interrupted if the user loses his grip of the spray nozzle handle. Today this safety function is so designed that the valve of the spray device opens by squeezing a control means in the form of a trigger in a loop. When the user loses his squeezing grip of the trigger, this springs back, whereby the valve closes and the jet of fluid is interrupted.

The design involving a handle with a loop and a trigger causes a great static load to the user's hand muscles when squeezing the trigger during the entire time of operation. When finishing the working day, as much as two hours may be needed for cleaning, which results in the static load on the hand muscles causing wear and industrial injuries.

To make the cleaning operation less strenuous, it happens that the safety function is eliminated by locking the trigger relative to the handle in an open position of the valve. Then the user just needs to hold the handle in a common grip and need not constantly squeeze the trigger towards the handle. If in this case the user should drop the handle in the cleaning operation, the high-pressure flow of fluid and an associated tube, through which the fluid is conducted to the spray device, may cause great damage to equipment and people standing nearby.

There are today no spray devices with nozzle and valve which provide the safety function without the design involving a trigger that is to be squeezed during the cleaning operation.

Spray devices with nozzle and valve as described above are disclosed in DE 35 27 922, DE 195 03 101, US-A-4,613,074 and GB 1,593,638. A drawback of these spray devices thus is that in operation they cause great static and ergonomically incorrect load to the muscles of the hand and the forearm.

Danish Utility Model Specification 95 00285 dis- closes a pistol handle for high-pressure appliances and high-pressure tools. This pistol handle is characterised in that the trigger has its turning point of the activat- ing wedge (trigger) placed behind the user's hand. With this construction, the force by which the user must press the trigger towards the handle would decrease since the hand is pressed forwards in the handle as the jet of high-pressure fluid operates. However, this construction suffers from, for instance, the drawback that the trigger must still be pressed towards the handle during the entire cleaning operation, which causes a static load to the muscles of the hand.

A further drawback of the prior-art spray devices with nozzle and valve is that the handle is not designed as a direct extension of the nozzle, which requires an unnatural position when planar surfaces are to be clean-

ed, which are located a distance above the plane on which the user is standing. Many users then often take a work- ing position in which they hold the tube behind their back and across their shoulder, the handle and the nozzle being held a distance in front of their shoulder with one hand. This cannot be done with today's spray devices for high-pressure sprayers when the safety function is active.

An object of the present invention is to provide a spray device with nozzle and valve which does not have the above drawbacks.

Other objects, features and advantages of the pre- sent invention will appear from the following specifica- tion.

These objects are achieved by a spray device with nozzle and valve according to appended claim 1. Parti- cularly preferred embodiments are defined in the depen- dent claims.

In brief, the present invention concerns a spray device comprising a valve and a nozzle for ejecting a jet of fluid. According to the invention, the spray device has a nozzle holder 6; 6, 15, 16, 19, which is adapted to be gripped manually when using the spray device and which is movable relative to the nozzle essentially in parallel with the direction of the jet of fluid. The spray device further comprises a valve, which is connected in front of the nozzle and is adapted to be opened when moving the nozzle holder in the direction of the jet of fluid rela- tive to the nozzle. The nozzle is biased in the direction of the jet of fluid relative to the nozzle holder 6, and the relative position of the nozzle holder to the nozzle is affected by the reaction power of the jet of fluid.

In a preferred embodiment of the present invention, a pressure spring is compressed between the nozzle and the nozzle holder to effect the bias.

The nozzle holder may comprise a sleeve, which by moving in the direction of the jet of fluid is adapted to open the valve.

An advantage of the present invention is that it does not cause static load and, thus, wear to the muscles of the hand and the forearm. A preferred embodiment of the present invention further has the advantage that the nozzle holder on the spray device is a direct extension of the nozzle. This embodiment of the present invention can thus be operated in a comfortable manner also when cleaning surfaces which are positioned above the plane on which the user is standing.

Preferred embodiments of the invention will be described below with reference to the accompanying draw- ings. The drawings are not to be considered to limit the scope of the present invention.

Fig. la is a sectional view of a preferred embodi- ment of the present invention, the valve being shown in a closed position, Fig. lb is a sectional view of the same embodiment as in Fig. la, but the valve is shown in an open posi- tion, Fig. 2a is a sectional view of a further preferred embodiment of the present invention, the valve being shown in a closed position, Fig. 2b is a sectional view of the same embodiment as in Fig. 2a, but the valve is shown in an open posi- tion.

Fig. 3a is a sectional view of a further embodi- ment of the present invention, the valve being shown in a closed position, Fig. 3b is a sectional view of the same embodiment as in Fig. 3a, but the valve is shown in an open posi- tion, Fig. 4a is a sectional view of one more embodiment of the present invention, the valve being shown in a closed position,

Fig. 4b is a sectional view of the same embodiment as in Fig. 4a, but the valve is shown in an open posi- tion, Fig. 5a is a part-sectional side view of a further embodiment of the present invention, the valve being shown in a closed position, Fig. 5b is a part-sectional side view of the same embodiment as in Fig. 5a, but the valve is shown in an open position, and Fig. 6 is a front view of a detail of the embodi- ment shown in Figs 5a and 5b.

The embodiments of the present invention shown in Figs la, lb, 3a and 3b comprise a spindle 1 with axial, non-connected bores 2, 3. The bores 2, 3 lead to open- ings 4, 5 in the outside of the spindle 1. The openings 4, 5 comprise in this embodiment radial openings from the bores 2, 3 out to the side of the spindle 1, but can also be designed in other ways that are obvious to one skilled in the art. The spray device according to Figs 1 and 3 further comprises a nozzle holder in the form of a sleeve 6, which is movable on the spindle 1. The sleeve 6 has an axially extended portion 7 with an increased inner radius. This portion can extend along the circumference of the spindle 1, but can also have a circumferential width corresponding to the openings 4, 5 and constitute one or more connections depending on the number of open- ings 4, 5.

The distance between the openings 4, 5 does not exceed the length of the portion 7 with an increased inner radius. Between the openings 4, 5, a lug 8 is arranged on the spindle 1. When the valve remains in its closed position, as in Fig. la, the lug 8 is adapted to engage an end wall 9 in the portion 7 with an increased radius. Like in Figs la, ib, 3a and 3b, this lug 8 may comprise a packing, but may also comprise a lug arranged in the material of the spindle 1. If the lug 8 is arrang-

ed in the material of the spindle 1, a packing can be arranged in the sleeve 6 instead of in the spindle 1.

The spray device shown in Figs la, lb, 3a and 3b further comprises a helical spring 10 compressed between a nozzle (not shown) which is fixed relative to the spin- dle 1, and the sleeve 6 to effect a bias which strives to displace the spindle 1 and the nozzle in the direction of arrow A relative to the sleeve 6. Between the sleeve 6 and the spindle 1, sealing packages are arranged, which comprise an 0 ring 11 and a Teflon ring 12. These sealing packages can be arranged in the sleeve 6, as shown in Figs la, lb, 2a and 2b, but can also be arranged in the spindle 1, as shown in Figs 3a, 3b, 4a and 4b. When open- ing the spray device, the sleeve 6 is moved axially in the direction of the helical spring 10, thereby forming a connection between the two bores 2, 3. The pressurised fluid flows through the bore 3, out of the spindle via the openings 4 and into the portion 7 with an increased inner radius in the sleeve 6, further through the open- ings 5 into the bore 2 and out through a nozzle (not shown). When a certain flow through the valve has been built up and the user holds the sleeve, the reaction power of the jet of fluid exerted on the nozzle will be greater than the power that the helical spring applies to the sleeve 6 relative to the nozzle. The spray device is thus kept in its open position by means of the reaction power of the jet of fluid as long as someone holds the sleeve 6. When the user loses his grip of the sleeve 6, the reaction power is no longer absorbed by the sleeve 6 and thus, there is nothing to counteract that the sleeve 6 is pushed backwards to a closed valve position by the helical spring 10.

The more the spring 10 is biased the better safety is obtained, but it must not be biased to such an extent in the open position of the valve that the sleeve 6 when operated is pushed back by the spring power in spite of the reaction power exerted by the jet of fluid on the

nozzle. To be able to compress the spring to a greater degree than allowed by the reaction power of the jet of fluid, it is possible, as shown in Figs 5a and 5b, to arrange a gear lever 15, 16, which, in opening, neutra- lises the extra spring force that is supplied by the spring 10. In the embodiment shown in Figs 5a, 5b and 6, the gear lever 15, 16 comprises a crowbar 15, which acts as a lever and is fixedly arranged on a piece of spring steel 16 by means of a rivet 17. The piece of spring steel 16 has a recess 18, the diameter of which is some- what larger than the outer diameter of the spindle 1 for receiving the spindle 1. The gear lever 15, 16 can, of course, be designed in other ways that are obvious to those skilled in the art.

In the embodiment of the present invention shown in Figs 5a and 5b, a handle 19 is displaceably arranged in the periphery of the spindle 1 and the sleeve 6. The handle 19 has a recess 20 for receiving the gear lever 15, 16. The recess 20 is designed such that the displace- ment of the handle 19 in the direction of the jet of fluid affects the gear lever 15, 16 which in turn affects the sleeve 6, which is moved towards the open position of the valve. The piece of spring steel 16 causes the crow- bar 15 to be held in place relative to the spindle 1, and the movement of the piece of spring steel 16 over the length of the spindle 1 is limited by a stop lug 21 arranged on the spindle 1. The stop lug 21 also consti- tutes an abutment surface for the crowbar 15 when opening the valve. The stop lug 21 can also be arranged to engage, when the handle 19 is moved in the direction of the jet of fluid, a wall 22 formed in the recess 20, which results in a limitation of the movability of the handle 19 relative to the spindle 1. Moreover, there may be arranged in the handle 19 in front of the sleeve in the direction of the nozzle (not shown) one more stop lug 23 which is adapted to engage the front edge of the sleeve 6 to determine the resting position of the handle

19 relative to the sleeve 6 and especially the gear lever 15, 16.

Thus, the gear lever 15, 16 generally constitutes some sort of gear, which is adapted to transform a move- ment of the handle 19 relative to the nozzle or the spin- dle 1 in the direction of the jet of fluid into a smaller movement of the sleeve 6 relative to the nozzle/spindle 1 in the same direction. In this embodiment, the nozzle holder thus comprises the handle 19, the gear/gear lever 15, 16 and the sleeve 6.

A different technique to be able to compress the spring to a greater extent than allowed by the reaction power of the jet of fluid is to arrange magnets in the seat 14 of the spring closest to the nozzle and at the edge of the sleeve 6 closest to the nozzle. This magne- tic force neutralises the extra spring force that the compressed spring 10 exerts in addition to the force that is neutralised by the reaction power of the jet of fluid.

As long as the user holds the sleeve 6, the magnetic force and the reaction power of the jet of fluid will hold the sleeve 6 in a position where the valve is kept open. When the user drops the sleeve 6, the spring force will neutralise the magnetic force and when the magnets have been moved apart a distance, no magnetic force is obtained, and the spring force presses the sleeve 6 back- wards with maximum force, thereby closing the valve.

The embodiments of the present invention shown in Figs 2a, 2b, 4a and 4b differ from the embodiments shown in Figs la, lb, 3a and 3b in such a manner that the spin- dle 1 has an increase in radius in the direction of the jet of fluid between the openings 4, 5. This increase in radius can be present anywhere between the two sealing packages 11, 12.

This design compensates for the pressure-dependent friction that is to be overcome in automatic closing of the spray device when the user drops the sleeve 6 or releases his hold of the sleeve 6 since the pressure-

absorbing area in the direction of the jet of fluid is smaller than the pressure-absorbing area in the opposite direction.

This is obvious from the embodiments shown in Figs 2a, 2b, 4a and 4b since the increase in radius is so great that the radius of the sleeve 6 changes corre- spondingly. The end wall 9 has a much smaller area than the end wall 13. The increase in radius of the spindle 1 need not be so drastic as shown in Figs 2a, 2b, 4a and 4b but can be so small that the inner radius of the sleeve 6 on either side of the portion 7 with an increased radius can be constant for the entire sleeve 6. The pressure- absorbing area depends generally on how great the dis- tance is between the portion 7 with an increased inner radius and the surface of the spindle 1 adjacent to the front and rear sealing packages 11, 12.

With the embodiment shown in Figs 4a and 4b having the sealing packages 11, 12 arranged in the spindle 1, the spindle 1 can have a constant diameter while the inner radius of the sleeve 6 after the portion 7 with an increased radius in the direction of the nozzle (not shown) can be greater than the inner radius of the sleeve 6 before the same portion 7, thereby achieving with dif- ferent pressure-absorbing areas the same effect as above.

The spray device with nozzle and valve according to the present invention thus has the advantages of not causing any static load, and therefore it does not cause wear to arise in forearms and hands.