High Pressure Washer With Detergent On-off Nozzle

Abstract

A portable high pressure washer is equipped with a length of hose and a turret nozzle having several manually selectable discharge orifices. One of the latter, the detergent orifice, is of greater size, while the remainder, the washing orifices, are of lesser size, than the throat diameter of a detergent injector located at the washer remote from the nozzle. Injection of detergent can thereby be controlled by the nozzle without the need of other means to activate or deactivate the injector, and at the same time the pressure of the detergent issuing from the nozzle is reduced.

Description

BACKGROUND OF THE INVENTION

High pressure washers, especially of the portable type, are currently widely marketed. Typical of some of these washers is a mobile cart upon which is mounted an electrically driven pump attachable to a supply of water, a container of detergent and an injector connected into the output of the pump and the container of detergent. To the outlet of the injector is fastened a length of hose at whose outer end is a nozzle of the turret type having a selection of orifices providing different spray angles at substantially the same flow rates and pressures. For obvious commercial reasons it is important to design the washer to be as simple and as inexpensive as is feasible, and one aspect of such a design is the manner by which injection of the detergent is controlled. One approach often used is a by-pass about the injector controlled by a valve, the valve being open when water only is desired and closed when detergent is desired. The valve and bypass of course add to the cost of the washer. Furthermore, the practice has been to make the flow rate of the detergent orifice of the nozzle the same as those of the washing orifices, only the spray angles of the latter being severally different. This results in the spray of detergent having substantially the same pressure as the various sprays of water only. But this is not desirable because the detergent should strike the work with less force in order not to "bounce off" and so impair its penetration and cleaning ability. Hence, the chief object of the present invention is to provide a simple, inexpensive means by which the injection of detergent can be controlled without need of a by-pass and valve at the injector and by which at the same time the pressure of the detergent issuing from the nozzle can be reduced.

SUMMARY OF THE INVENTION

The foregoing object and others are achieved by providing the nozzle with different sized orifices, one of which is larger than the throat diameter of the injector, while the other or others are smaller than the latter. Hence, in the one case, the pressure drop through the injector is greater than that across the nozzle orifice so that detergent is injected into the hose. At the same time, the pressure of the detergent and hence the force with which it strikes the work is thereby reduced. In each of the other cases, however, the pressure drop through the nozzle orifice is greater than that through the injector and hence no detergent is injected into the hose.

The invention is readily incorporated into a turret nozzle. In a preferred form of the invention, a cylindrical head at the downstream end of the nozzle is provided with four orifices, the head being manually rotatable to selectively bring one orifice at a time into communication with the hose. Three of the orifices are relatively small, their diameter being less than that of the throat of the injector which is of the Venturi type. All of the three provide washing fluid only, usually water, at a very high pressure, one of the three producing a "jet" of water upon a relatively small area, while the other two produce fan-shaped sprays of water of different angles over relatively greater areas, all to accommodate different washing demands. The remaining orifice, larger than the other three and also larger than the injector's throat, provides a spray of both water and detergent at much lower pressure. By rotating the head, therefore, to select the appropriate orifice, the pressure of the detergent can be reduced and its flow controlled without requiring a by-pass and valve about the injector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portable washer according to the present invention.

FIG. 2 is a partially exploded, perspective view of the wheeled cart upon which the washer's components are mounted.

FIG. 3 is an exploded perspective view of the mechanical components of the washer illustrating their assembly and relationships.

FIG. 4 is an exploded perspective view of the nozzle employed with the washer of the present invention.

FIG. 4A is a view taken from the line 4A--4A of FIG. 4.

FIG. 5 is a schematic diagram of the electrical circuit controlling the washer.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The components of the washer are carried on a wheeled cart 10 (see FIGS. 1 and 2) having a floor pan 11 reinforced by flanges 12 along its side edges and a transverse channel 13 parallel to its front and rear edges. Rearward of the channel 13 are located a pair of wheels 14 (one only being shown) journaled on a transverse axle 15, and beneath the front edge of the floor pan 11 is a stand 16. A pair of front and rear end panels 17 and 18 having side flanges 19 are appropriately mounted along the front and rear edges of the floor pan 11. The rear end panel 18 is louvered at 20 and fitted with an upstanding handle 21 of inverted U-shape between whose uprights 21a is a cross-piece 22. A U-shaped cover 23 for the electrical components is secured to the inner face of the front end panel 17, and over the end panels 17 and 18 and partially down their sides 19 is a cover 24 to whose top and to the handle uprights 21a are fastened three hose coiling brackets 25. It will be understood that the cart 10 is preferably fabricated from appropriate sheet metal and secured together by screws and welds.

Turning now to FIG. 3, the mechanical components of the washer are mounted on a base plate 30 screwed to the floor pan 11 within the cart 10. These components include a three-fourths h.p., 115 VAC electric motor M, internally fitted with a suitable overload protective device, and a two-piston, positive displacement pump P capable of delivering 2 gal/min. at 500 p.s.i.g. at 1140 rpm pump speed. The pump P is driven by a belt 31 and sheaves 32, 33 by the motor M, the mounting of the latter including slotted holes 34 in the base plate 30 and a sliding channel 35 for adjusting the tension of the belt 31 by means of a screw 36, all as is typical practice. The inlet to the pump P is provided with an elbow 37 and one end of a short length of hose 38 to whose other end is fixed a water valve V operated by a solenoid S of conventional type. To the inlet of the valve V is connected a female hose coupling 39 at one end of another short length of hose 40, the latter passing through a grommet 41 (see FIG. 2) in the front end panel 17 of the cart 10 and equipped at its outer end with another female hose coupling 42. The output of the pump P, in turn, is connected by fittings 43, which pass through a grommet 44 (see FIG. 2) also in the front end panel 17, to one end of a typical Venturi type injector I having a throat 45 and an inlet 46 thereto. A short length of plastic hose 47 is connected to the inlet 46 and enters one of two bottles of detergent 48 carried atop the cover 24 and retained against the cross-piece 22 by an elastic band 49 about the handle uprights 21a and the bottles 48. The output of the injector I is connected by suitable fittings 50 to a length of hose 51 connected at its outer end to a wand 52 having a handle 53 at its rear end and a turret nozzle N at its forward end.

The nozzle N (see FIGS. 4 and 4A) consists of an integral body 54 having a shank 55, axially bored at 56, a female hose coupling 57 at its rear end, and a circular plate 58 at its forward end eccentrically disposed with respect to the axis of the bore 56 through which the latter opens. The bore 56 seats the rear end of a spring 59 within whose forward end in turn sits a jet 60 sealed to the bore 56 by an O-ring 60a, the jet 60 having a forward nose engaging alternate ones of four counterbores 61 in the rear face of a rotatable cylindrical head 62. The counterbores 61 are equally spaced about the axis of the head 62 and selectively alignable with the bore 56. The head 62 is drilled forwardly therethrough from the counterbores 61 to provide four orifices, 63 - 66, in its front face. Radially across the forward end of the orifice 63 is a flat bottom channel 67 providing a "0.degree." spray or "jet." Diametrically across the forward ends of the orifices 64 and 66, however, is a V-shaped channel 68 providing a 15.degree. spray while radially across the forward end of the orifice 65 is a v-shaped channel 69 providing a 40.degree. spray. The nozzle N is assembled by means of an internally threaded retaining ring 70 having a shoulder 71 engaging the rear face of the plate 58, the retaining ring 70 receiving an externally threaded boss 72 of the rear face of a squared plate 73 having an aperture 74 through which the forward end of the head 62 protrudes. The head 62 is held against rotation relative to the plate 73 by means of complementary flats 75 about the head 62 and the forward end of the aperture 73. Hence, rotation of the plate 73 will also rotate the head 62 to selectively bring each of the four orifices, 63 - 66, into alignment with the jet 60.

In the example shown, three of the orifices, 63, 64 and 65, which are those for water only, each have a diameter of 0.055 inches and a flow rating of 0.55 gal/min. at 40 p.s.i.g., while the fourth, 66, which is that for both water and detergent, has a diameter of 0.15 inches and a flow rating of 1.5 gal/min. at the same pressure, the diameter of the throat 45 of the injector I being 0.081 inches. Since the diameter of the throat 45 of the injector I is greater than that of each of the orifices 63 - 65, while smaller than that of the orifice 66, only when the latter is selected will detergent be injected into the hose 51 and at the same time issue at reduced pressure from the nozzle N. In the case given, the flow through the washing orifices 63 - 65 is about 2 gal/min. at 500 p.s.i.g., while that through the detergent orifice 66 is about 2.0 gal/min. at 90 p.s.i.g.

The electrical components, besides the motor M and the solenoid S, include a three-wire cable and plug 80 which enters the front end panel 17 of the cart 10 through a grommet 81 behind the cover 23. One wire 82 of the cable 80 is grounded as indicated in FIG. 2 to the cart 10, while a pair of two-wire cables 83 and 84 from the motor M and the solenoid S are each connected to the remaining two wires of the cable 80 and a three-position, d.p.d.t. switch SW in the manner shown in FIG. 5. As will be noted, the two poles of the circuit making member of SW are connected by a jumper 85, while the two poles of the side of SW to which the solenoid S only is connected are joined by another jumper 86. Hence, as will be observed, in one circuit making position of SW only the solenoid S is activated to prime the pump P while in the other both the motor M and the solenoid S are activated to provide full operation.

To use the washer, the coupling 42 is connected to an ordinary garden hose from a water tap and the cable and plug 80 to a suitable 115 VAC outlet. The hose 47 is placed in one of the detergent bottles 48 and the appropriate orifice of the nozzle N is selected by rotation of the plate 73 by which, as explained above, the flow of detergent is also controlled without need of any valve, by-pass or other device at the injector I for that purpose. SW is then thrown first to activate the solenoid S only and thus open the water valve V. The pump P is thereby primed and all air expelled from the system by the incoming water. When priming is complete, SW is thrown to its other position which additionally activates the motor M and pump P. The washer is then ready for work. Should the system become clogged, thus tending to overload the pump P and the motor M, the latter will shut off of its own accord owing to its internal protective overload provision.

Before changing from one orifice to another it is necessary first to shut off the pump P by means of the switch SW in order to prevent high pressures at the nozzle N from damaging or destroying its O-ring seal 60a. This of course requires the operator to return to the cart 10 each time to do so. If this is undesirable, the wand 52 can be fitted with a suitable switch in series with the motor M so that the pump P can be controlled without need for the operator to return each time to the cart 10, the latter being connected to the wand switch by means of a cable running together with the hose 51.

Though the invention has been described in terms of a particular embodiment, being the best mode known of carrying out the invention, it is not limited to that embodiment alone. Instead, the following claims are to be read as encompassing all adaptations and modifications of the invention falling within its spirit and scope.

Claims

I claim:

1. In a pressure washer having a drivable pump connectable to a source of washing fluid and a length of flexible conduit and an injector connected in fluid flow relation to the fluid output of said pump, said injector including a Venture therein providing a pressure drop in said washing fluid flowing therethrough and connectable to a supply of cleaning fluid for injection thereof into said conduit, the improvement comprising: fluid discharge means downstream of said conduit and remote from said washer, said discharge means selectively providing a pressure drop in said washing fluid smaller than that provided by said Venturi and an alternate pressure drop in said washing fluid greater than that provided by said Venturi in order to control injection of said cleaning fluid into said conduit, and means to select one or the other of said pressure drops.

2. The combination of claim 1 wherein said fluid discharge means is a nozzle disposed at the downstream end of said conduit, said nozzle having alternate fluid passages therein, a first one of said passages providing said smaller pressure drop and another one of said passages providing said greater pressure drop.

3. The combination of claim 2 wherein said fluid passages comprise discharge orifices in alternate fluid communication with said conduit.

4. The combination of claim 3 wherein said pump is of the positive displacement type, said first one of said orifices having a greater flow rate than said other orifice, whereby the pressure of fluid issuing from said first orifice is less than that of the fluid issuing from said other orifice.

5. The combination of claim 4 wherein said orifices are disposed in a movable member constituting a part of said nozzle, said selecting means including said movable member.

6. The combination of claim 5 wherein said movable member comprises a head rotatable about an axis, said orifices being disposed in said head in radially spaced relation with respect to said axis, said head rotation providing alternate fluid communication of said orifices with said conduit.