SPRAY GUN WITH ADJUSTMENT OF THE SHAPE OF THE JET

Abstract: The gun has a delivery opening (4) with a nozzle (7) which can be opened and closed for the delivery of the liquid to be sprayed. A diffusing member (21) is associated with the opening (4) downstream from the nozzle (7) so as to vary the conformation of the jet of the liquid.

Description: This invention refers to a spray gun with adjustment of the shape of the jet. As is well known, spray guns are constituted by a delivery pipe connected to a hollow handgrip through which the liquid to be sprayed passes. The delivery pipe terminates at its front end with a spray opening with a nozzle at its centre through which the liquid is delivered. Inside the delivery pipe there is a movable member for closing and opening the nozzle, said member being operated from the outside by means of appropriate control levers. The adjustment of the flow of the liquid is obtained by operating the member for opening and closing the nozzle, namely, when the nozzle is open the delivered spray jet will have a limited diameter and range but with larger droplets while when the nozzle is partially closed the delivered spray jet will have a larger diameter and range but with finely dispersed droplets. The spray jet issuing from the nozzle has a circular shape and tends to concentrate on a larger or a smaller circular area in relation to the nozzle opening and to the distance between the surface to be sprayed and the gun. With this type of spray gun, for example as disclosed in US-A-4448355, it is not, however, possible to deliver flat-shaped spray jets with which it is possible to cover an area larger than with a circular spray jet. It is also known from US-A-4 380 319 to provide a liquid spray apparatus with an adjustable diffusing member which is used to vary the conformation of the jet of the liquid, the diffusing member is arranged down stream from the nozzle. Given this state of the art, the object of the present invention is to realize a spray gun which can vary the shape of the delivered spray jet, in particular so that it is possible to transform the spray jet, in adjustable way it as required, from a circular shape to a fan shape. According to the invention, such object is attained by a spray gun which includes a delivery pipe connected to a hollow handgrip through which the liquid to be sprayed arrives, said pipe terminating at its front end with an opening provided with a nozzle which can be opened or closed for the delivery of the liquid contained in said pipe, characterized in that said opening includes an adjustable diffusing member arranged downstream from the nozzle in order to vary the conformation of the liquid jet issuing from said nozzle, said diffusing member comprising two flat and parallel tangs or feathers, which can be moved closer or farther apart from one another by means of a tightening sleeve collar which engages the outer part of said tangs. The tip of said tangs preferably extends towards the outlet of the opening while the rear end is fastened to the wall of the delivery pipe with the nozzle. One possible embodiment of the present invention is illustrated as an example which is not restrictive in the enclosed drawings where: fig. 1 shows a partially sectioned side view of a spray gun according to the invention; fig. 2 shows a side view of a diffusing member, included in said gun, enlarged and partially sectioned; figs. 3 and 4 are a right-hand view and a top view, respectively, of the diffusing member shown in fig. 2; fig. 5 shows a tightening sleeve collar included in the above gun, enlarged and sectioned along the line V-V in fig. 6; fig. 6 is a rear view of the above tightening sleeve collar; fig. 7 shows an enlarged front view of the opening of said gun from the right-hand side in relation to fig. 1 and in the position of delivery of a circular spray jet; fig. 8 shows an enlarged front view of said opening in the position of delivery of a flat spray jet. Fig. 1 shows a spray gun constituted by a hollow handgrip 1 connected to a delivery pipe 2. At the base of the handgrip there is a coupling 3 for connecting a means (not shown) for feeding the liquid to be sprayed. The delivery pipe 2 is equipped at one end with a spraying opening 4 and at the other end there is a trigger 5 which operates a closing and opening member 6 of a circular nozzle 7 arranged on the longitudinal axis of the front opening 4. Said opening and closing member 6 is constituted by a rod 8 with, at one end, a plug 9 for the nozzle 7 and, at the other end, a tip 10 which engages said trigger 5. The upper part of the latter has an opening 11, through which the rod 8 passes, said opening forming two lateral arms 12 which come together at the top, so that the tip 10 is pressed against said arms 12 by the action of a spring 13 contained in the delivery pipe 2. In turn, the arms 12 press against the rear end of the delivery pipe 2 which is closed by a ring nut 14. The trigger 5 hinges on a pin 15 which is secured in a protrusion 16 of the handle 1. The tip 10 of the member 6 has lateral indentations 17 which engage with a complementary indentation 18 on a flexible portion 19 which passes through the trigger opening 11 and is secured at one end on said protrusion 16 around the pin 15. The opening 4 at the front end of the delivery pipe 2 includes a tightening sleeve collar 20 which can rotate on a plastic diffusing member 21 integral with the casing 22 of the delivery pipe 2. Said casing 22 has a choke or neck 55 for the nozzle 7. The diffusing member 21, as shown in figs. 2, 3 and 4, consists of two flexible tangs or feathers 23 which are cantilevered over the choke 55 of the pipe 2 and have side protrusions 24 from which the tapered teeth 25 extend towards the tips 26 of the tangs themselves. The tightening sleeve collar 20 (fig. 5) can rotate on said diffusing member 21 and for this object said collar has separate spiral arc seats 27 (fig. 6) inside it which can receive the tapered teeth 25 of the diffusing member 21. Said seats 27 have side walls 28 and 29 and a bottom 31 the external side walls 28 being defined by the casing 32 of the sleeve collar while the internal side walls 29 are defined by a flanged opening 33 contained within the sleeve collar, whose flange 34 is connected to the casing 32 of the sleeve collar and constitutes the bottom 31 of said seats 27. Said opening defines a passage 35 for the tangs 23 of the diffusing member 21. Each seat 27 is arranged along a spiral arc (fig. 6) and has two extremities 43 and 44 of which a first extremity 43 is at a radial distance from the longitudinal axis of the passage 35 which is greater than the distance existing between said axis and the second extremity 44. In addition the extremities 43 of each seat 27, in the same way as the extremities 44, are arranged in a diametrically opposite position, that is to say, the extremities 43 of the two seats 27 are aligned along the same line which passes through a diameter of the passage 35. The rear end 36 of the sleeve collar 20, as shown in fig. 5, has a ring-shaped protrusion 37 which penetrates in a circumferential groove 3 on the outside of the casing 22 of the delivery pipe 2 (figs. 2 and 4). From said rear end 36 a tooth 38, whose function will be described below, protrudes longitudinally. The front end 39 of the sleeve collar 20 has a ring element 40 with a diverging internal wall at whose extremities there are notches 41 for the passage of the water when the opening is arranged for the delivery of a fan-shaped spray jet as will be described below. The external surface of the casing 32 of the sleeve collar 20 has small longitudinal grooves 42 which are uniformly distributed and have a decreasing depth as they get closer to the sleeve collar's front end 39 so that it is easier to manipulate during the adjustment of the spray jet. The spray gun described herein operates as follows. In the position shown in fig. 1 the gun is at rest and the sleeve collar 20 is rotated to a position such that the teeth 25 of the diffusing member 21 are near the radially most external extremities 43 of the spiral seats 27 and thus keep the tangs 23 (fig. 7) at a certain distance from one another. Water coming from the hollow handgrip 1 and contained in the delivery pipe 2 is not sprayed outside since the nozzle 7 is closed by the plug 9 of the opening and closing member 6 due to the action of the spring 13. When the trigger 5 is pressed the arms 12 of the trigger 5 are made to move the tip 10 towards the outside against the action of the spring 13 while the indentation 17 jogs along the indentation 18 of the flexible part 19 and stops in the required position. At the same time the plug 9 moves backwards and releases the nozzle 7 and water will issue from the latter. Since the nozzle is circular and the tangs 32 are at a certain distance from one another, the spray jet issuing from the opening 4 has a circular shape and passes, without being intercepted, in between the tangs 23 of the diffusing member 21 and thus takes an almost circular shape. If a flattened, fan-shaped spray jet is required it is only necessary to rotate the sleeve collar 20 so that the teeth 25 of the diffusing member 21, as they move along their seats 27, reach the extremities 44 of the seats 27 while getting closer to the axis 35 of the passage and press the tangs 23 of said diffusing member 21 towards the sides, which thus move closer together (fig. 8). The tangs 23 will, in this way, be in the path of the jet which is thus intercepted and flattened. In this position the notches 41 inside the ring portion 40 of the sleeve collar 20 are arranged alongside the slot defined by the tangs 23, so that an optimum lateral widening of the issuing spray jet is obtained. In addition, the tooth 38 in the rear part of the sleeve collar 20 has, when the sleeve itself is rotated, gone through an arc of a circle and is now on the opposite side of the gun, thus signalling that the opening 4 is ready for a fan-shaped spray jet. When the circular spray jet is once more required the sleeve collar 20 is rotated in the opposite direction, thus moving the tangs 23 away from one another since the teeth 25 of the diffusing member 21 move along the seats 27 and reach their extremities 43. It is obviously possible to adjust the spray jet, that is the reciprocal movement of the tangs 23, by partially rotating the sleeve collar 20 so that the teeth 25 move only part of the way along their seats 27.

Claims: 1. Spray gun including a delivery pipe (2) connected to a hollow hand grip (1) through which the liquid to be sprayed passes, said delivery pipe (2) having at the front an opening (4) provided with a nozzle (7) which can be opened and closed for the delivery of the liquid contained in the delivery pipe (2), characterized in that said opening (4) includes an adjustable diffusing member (21) arranged downstream from the nozzle (7) so as to vary the shape of the liquid jet issuing from said nozzle (7), said diffusing member (21) including two flat and parallel tangs (23) which can be moved closer and farther away from one another by means of a sleeve collar (20) with a casing (32) which engages the outside of said tangs (23). 2. Spray gun according to claim 1 characterized in that said tangs (23) have a tip (26) which extends towards the outlet of said opening (4) and the rear extremity is fastened to the outlet of said delivery pipe (2), said tangs (23) having also lateral protrusions (24) from which the tapered teeth (25) extend towards the tips of the tangs themselves and said sleeve collar (20) can rotate on said diffusing member (21) and has two separate spiral arc seats (27) inside it which can receive the tapered teeth (25) of said diffusing member (21), said seats (27) having external and internal side walls (28) and (29) and a bottom (31) in which the external side walls (28) are defined by the casing (32) of the sleeve collar (20) and the internal side walls (29) are defined by a flanged opening (33) contained within said sleeve collar (20), the flange (34) of said opening (33) being connected to the casing (32) of said sleeve collar (20) and constituting the bottom (31) of said seats (27), said opening defining a passage (35) for the tangs (23) of the diffusing member (21). 3. Spray gun according to claim 2 characterized in that each spiral arc seat (27) has two extremities (43 and 44) of which a first extremity (43) is at a radial distance from the longitudinal axis of the passage (35) which is greater than the distance existing between said axis and the second extremity (44), said first extremities (43), in the same way as said second extremities (44), being arranged in a diametrically opposite position. 4. Spray gun according to claim 3 or 4 characterized in that the clamping sleeve collar (20) has a frontal portion (40) with a flared internal wall, whose extremities have opposite radial notches (41).

Inventors: ROMAN, GIANFRANCO
Applicants: CLABER S.P.A.
Application year: 1988
Main classification: B05B9
IPC codes: B05B1, B05B9