GB2296670A - Spraying device - Google Patents

Abstract

A spraying device comprising a rotary spray head which is adapted to be rotationally driven by a flow of water and is journalled on a hollow shaft (2), the rotary spray head comprising a base disc (4) on which is superposed a combined motivator disperser unit (6), comprising at least one face adapted to deflect water radially and at least one face adapted to rotationally drive the rotary spray head. The shaft is in the form of a retainer spindle and has a radial projection (8) which is received loosely between opposed surfaces of the base disc (4) and the motivator disperser unit (6) so that the rotary spray head is retained on the shaft but can rotate relative thereto. <IMAGE>

Description

DESCRIPTION SPRAYING DEVICE The present invention relates to the spraying of liquids, and in particular to rotary spraying devices which disperse liquids over a circular area for watering lawns and gardens.

A number of sprinklers or spraying devices are known which are adapted to be connected to a water hose and to distribute a spray of water droplets over a area of land. It is desirable that the water should be distributed evenly, and to this end a known type of spraying device comprises a rotary spray head upon which a flow of water impinges. The face or faces of the rotary spray head upon which the water impinges deflect the water outwards, forming a diffuse spray, and at the same time cause rotation of the rotary spray head so that the spray is evenly distributed over a 360 arc around the spraying device.

This type of spraying device is exemplified in GB194300, which describes a rotary watering spray wherein an ejection socket provided with aluminium wings or paddles is rotatably mounted using a ballbearing.

One important problem with known devices of this type is the complexity of their construction, which makes the known devices expensive. For example, the device illustrated in GB194300 comprises at least 8 metal components and a ball-bearing so that the production cost would clearly be large.

One object of the present invention is to provide a spraying device of simple, compact and, therefore, cheap construction.

A particular problem in achieving this is to provide a rotary mounting for the rotary spray head which is low friction (since the torque exerted on the spray head is not large) and is simple and cheap to construct and assemble.

According to the present invention, there is provided a spraying device comprising a rotary spray head which is adapted to be rotationally driven by a flow of water and is journalled on a hollow shaft, the rotary spray head comprising a base disc on which is superposed a combined motivator disperser unit.

In some embodiments, the combined motivator disperser unit is rigidly mounted on the base disc, for example by screws. In other embodiments, the motivator disperser unit can be integrally coupled to or integrally formed with the base disc.

Preferably, the shaft is in the form of a retainer spindle and has a radial projection which is received loosely between opposed surfaces of the base disc-and the motivator disperser unit so that the rotary spray head is retained on the shaft but can rotate relative thereto.

This method of construction makes possible a particularly simple spraying device which may have as few as three components. Assembly of the spraying device according to the present invention is also cheap and simple: the shaft is inserted into a central hole in the base disc in which it is journalled, and then the motivator disperser unit is attached to the base disc with said radial projection of the shaft trapped therebetween.

Preferably, the radial projection is at or adjacent an end of the shaft.

Preferably, the radial projection is formed as an annular lip.

Preferably, the rotary spray head is journalled at a portion thereof adjacent to a face or to faces of the motivator disperser unit upon which the flow of water impinges in use.

This configuration, facilitated by the mode of construction according to the present invention, has been found to be particularly advantageous since the forces exerted upon the rotary spray head include not only a desirable driving moment acting perpendicular to the axis of rotation (which causes rotation of the spray head) but also, typically, a twisting movement acting in a plane containing the said axis. This twisting moment increases friction and wear of the spray head journal, and may cause the spray head to vibrate or to bind. Its magnitude, when considered about the spray head journal, is minimised by placing the journal close to the faces upon which the water impinges.

Preferably, the base disc consists of a respective single plastics moulding made of a lightweight bearing material with corrosion resisting properties.

Preferably, the motivator disperser unit is made of a plastics material.

Preferably, the motivator disperser unit comprises at least one face adapted to deflect water radially and at least one face adapted to rotationally drive the rotary spray head.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a first embodiment of disc-mounted, motivator disperser in accordance with the present invention; Fig. 2 is cross-section along the line A-A of Fig. 1; Fig. 3 is a perspective, partially cut-away view of a second embodiment in accordance with the present invention; Fig. 4 is a perspective, partially cut-away view of a third embodiment in accordance with the present invention; and Fig. 5 is a sectional side-elevation of a fourth embodiment in accordance with the present invention.

The first embodiment of the present invention depicted in Figures 1 and 2 comprises a shaft 2, preferably of a corrosion resistant material such as stainless steel or a rigid plastics, upon which is journalled a rotary head comprising a disc 4 and a motivator disperser element 6. The disc 4 and the motivator disperser 6 each comprise in this embodiment, a respective single plastics moulding.

As Fig. 2 shows, the shaft 2 has a through-going axial bore 2a and broadens at its upper end into a radially outwardly projecting flange or lip 8.

The disc 4 is penetrated by a through-going axial bore 4a in which the shaft 2 is a running fit, and which broadens at a shoulder 10 into a shallow counterbore 19 within which the lip 8 is located. The inner diameter of the counterbore 19 is larger than the outer diameter of the lip 8 so that there is small clearance around the outer periphery of the lip 8.

The motivator disperser element 6 according to the present embodiment of the invention comprises two attachment lugs 14a, 14b and an integrally formed turbine portion 16. The turbine portion 16 comprises two planar drive faces 18 which extend radially and are diagonal to the axis of rotation of the rotary head. The radially inner edge of each planar drive face 18 is defined by a vertex with a respective deflector face 20. the two deflector faces are upwardly divergent, as Fig. 2 makes clear, and their bottom edges are parallel and lie on a line which passes through and is perpendicular to the axis of rotation of the rotary head.

The motivator disperser element 6 is attached to an upper face 4a of the disc 4. In the illustrated embodiment of the present invention, this attachment is by means of two screws 12 which are a clearance fit within vertical holes (not shown) in the attachment lugs 14 and are threadedly received in two corresponding holes (not shown) in the disc 4. Other suitable attachments means will be known to those skilled in the art. For example, the motivator disperser element 6 could comprise, at its base, a disc bearing an external thread to be threadedly received in a shallow bore in the upper face 4a of disc 4.

During assembly of the rotary spray head, the shaft 2 is first inserted into the through going axial bore 4a in the disc 4 and the motivator disperser element 6 is then attached to the upper face 4a of the disc 4. The lip 8 is retained between a lower face of the counterbore 19 in the disc 4 and lower surface of the motivator disperser 6, so that the spray head is retained on the shaft 2. In a typical application of the above-described specific embodiment of the present invention, the shaft 2 is sealingly attached to a tube or garden hose through which pressurised water is supplied, the rotary spray device being thereby mounted with the rotational axis of the rotary spray head upright.

Water is passed through the tube or garden hose and through the shaft 2, exiting through the top of the shaft and impinging upon the planar drive faces 18 and the deflector faces 20 of the motivator disperse element 6.

The deflector faces 20 deflect the flow of water diagonally outwardly, producing a diffuse spray which will cover a large circular area of land around the spray head, while the impact of the flow of water upon the drive faces 18 causes the drive head 6 to rotate, thereby providing an even distribution of water over said circular area.

The motivator disperser device 6 may take a variety of different forms without departing from the scope of the present invention. For example, in a second specific embodiment of the present invention illustrated in Fig 3 the motivator disperser 6 comprises four vertically extending planar vanes 20 disposed in a circular arrangement around the axis of rotation of the spray head on a support plate 21.

Each of the vanes 20 is diagonal to a radial direction. The vanes 20 collectively support deflector member 22 formed as an upwardly divergent cone, the axis of symmetry of which is parallel to the axis of rotation of the spray head. When this embodiment of the present invention is used, water exits from the top of the shaft 2 and is deflected radially outwardly by the conical deflector member 22, impacting against the planar vanes 20 and thereby rotating the spray head.

In the embodiment of Fig. 3, the hollow shaft 2 is connected at its lower end to a further disc 23 which connects the spray head to a conventional plastics retainer socket 24 by which the spray head can be coupled detachably to a hose pipe or other water supply pipe (not shown).

The embodiment of Fig 4 is essentially the same as that of Fig 3 in principle but uses eight vanes 20a in place of the four vanes 20 used in the embodiment of Fig. 3. The vanes 20,20a can either be integral with the conical deflector 22 as shown in Fig 4 or be formed separately from the deflector 22 as shown in Fig 3.

Fig. 5 shows a modified version of the embodiments of Figs 3 and 4 wherein, in order to improve the bearing support efficiency for the disc 4 on the shaft 2, the shaft 2 has an annular recess 26 formed immediately beneath the flanged lip 8 and the disc 4 has an annular recess 27 formed immediately radially outwardly of the flanged lip 8. This embodiment also includes the provision of a low friction washer 29 between the lower surface 4b of the disc 4 and a support member 31 which the rotary spray head is mounted in use, and a further annular recess 30 in the lower surface 4b of the disc 4 immediately radially outwardly of the washer 29.

Claims (11)

1. A spraying device comprising a rotary spray head which is adapted to be rotationally driven by a flow of water and is journalled on a hollow shaft, the rotary spray head comprising a base disc on which is superposed a combined motivator disperser unit.

2. A spraying device as claimed in claim 1, in which the combined motivator disperser unit is rigidly mounted on the base disc.

3. A spraying device as claimed in claim 1, in which the motivator disperser unit is integrally coupled to or integrally formed with the base disc.

4. A spraying device as claimed in any of claims 1 to 3, in which the shaft is in the form of a retainer spindle and has a radial projection which is received loosely between opposed surfaces of the base disc and the motivator disperser unit so that the rotary spray head is retained on the shaft but can rotate relative thereto.

5. A spraying device as claimed in claim 4, in which the radial projection is at or adjacent an end of the shaft.

6. A spraying device as claimed in claim 4 or 5, in which the radial projection is formed as an annular lip.

7. A spraying device as claimed in any of claims 1 to 6, in which the rotary spray head is journalled at a portion thereof adjacent to a face or to faces of the motivator disperser unit upon which the flow of water impinges in use.

8. A spraying device as claimed in any of claims 1 to 7, in which the base disc consists of a respective single plastics moulding made of a lightweight bearing material with corrosion resisting properties.

9. A spraying device as claimed in any of claims 1 to 8, in which the motivator disperser unit is made of a plastics material.

10. A spraying device as claimed in any of claims 1 to 9, in which the motivator disperser unit comprises at least one face adapted to deflect water radially and at least one face adapted to rotationally drive the rotary spray head.

11. A spraying device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.