GB2147974A

GB2147974A - Flow control valve

Info

Publication number: GB2147974A
Application number: GB08326313A
Authority: GB
Inventors: Peter John Donnelly; John Brooks Callard
Original assignee: Hills Ltd
Current assignee: Hills Ltd
Priority date: 1983-09-30
Filing date: 1983-09-30
Publication date: 1985-05-22
Also published as: GB8326313D0

Abstract

A horticultural sprayer includes a flow control valve comprising a housing 1 containing a manually depressable valve closure plunger 8 urged into a fully closed condition by a compression spring 9 and movable between that condition, in which a latching pin 18 thereof abuts respective base surface portions of respective recesses 19 in an annular end face of the housing 1, a partly-open condition in which the pin 18 abuts respective intermediate surface portions of the recesses 19, and a fully-open condition in which the projection 18 abuts respective surface portions of the end face, by turning of the plunger 8 about its own axis by means of a knob 17. In the fully closed condition of the plunger 8, the pin 18 can occupy a position in which the plunger 8 is prevented from being opened, owing to abutment of the pin 18 against respective undercut surface portions of the recesses 19. <IMAGE>

Description

SPECIFICATION A fluid-flow control valve According to the present invention, there is provided a manually operable fluid-flow control valve comprising a housing, a valve port in said housing, a valve closure member manually movable between a closed condition in which said member closes said valve port and an open condition, biassing means urging said member in the direction from said open condition to said closed condition, and latching means which can be manually rendered effective and ineffective to maintain said member latched in said open condition against the action of said biassing means.

The open condition can be a partly-open condition or a fully-open condition.

In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which Figure 1 shows a vertical sectional view through a liquid-flow control valve of a horticultural sprayer, with a valve closure member in a latched-closed condition, Figure 2 is a fragmentary view similar to Fig. 1, but with the valve closure member in a condition in which it is closed but its degree of opening is manually adjustable, Figure 3 is a view similar to Fig. 2, but with the valve closure member latched into a condition in which it is at least half-open, and Figure 4 is a view similar to Fig. 2, but with the valve closure member latched in a fully open condition.

Referring to the drawings, the manually operable liquid-flow control valve includes a housing 1 comprising an inlet part 2 onto which can be secured a flexible hose (not shown) leading from a vessel containing liquid under pressure, a valve chamber part 3 the interior of which is in the form of a vertical bore 4 communicating with a horizontal axial bore 5 of the part 2, and an outlet part 5 into which can be screwed a sprayer lance (not shown) leading to a sprayer nozzle. The bore 4 communicates with a horizontal off-centre bore 6 of the part 5 leading to a wider, axial bore 7 thereof. Arranged co-axially in the bore 4 is a valve closure plunger 8 which can be manually pressed downwards against the action of an encircling return spring 9. The spring 9 acts between a downwardly facing shoulder 10 of the plunger 8 and an upwardly facing shoulder 11 of the part 3.Fixed to the upper end of the plunger 8 is a button 1 2 which can be manually pressed downwards until it abuts against the top of the part 3 to limit downward movement of the plunger 8 and thus define the fully open condition of the plunger 8, in which the bores 5 and 6 are both fully open onto an annular recess 1 3 around the plunger 8. Liquid is prevented from escaping from the top of the bore 4 by means of an "O"-ring seal 14 and from the bottom of the bore 4 by an "O"-ring seal 15.

Moreover, an "O"-ring seal 16, also encircling the plunger 8, prevents liquid from escaping from the bore 5 to the bore 6 in the closed condition of the plunger 8. The bottom end of the plunger 8 has fixed thereto a setting knob 17, whereby the plunger 8 can be manually turned about its own axis to set it into any one of a number of conditions. Fixed diametrically through the plunger 8 near its lower end, and projecting from both sides thereof is a pin 18, the projecting ends of which are engageable in respective, diametrically opposite slots 1 9 formed in the lower end of the part 3.Each slot 1 9 comprises a portion 19' extending peripherally of the lower end of the part 3, a portion 19" extending longitudinally of the part 3 inwardly from the portion 1 9', and a portion 19"' extending peripherally from the portion 19" in a sense away from the portion 19' and at a spacing from the lower end of the part 3. In the condition shown in Fig. 1, the plunger 8 is latched substantially in its fully closed position, because each projecting end of the pin 1 8 is located in the portion 19"' and thus the plunger 8 cannot be pressed downwards out of that position. Such an arrangement prevents accidental opening of the valve, and thus spraying of the liquid, owing to inadvertent depression of the plunger 8.

In the condition of the plunger 8 shown in Fig. 2, the knob 1 7 has been turned anticlockwise through approximately half a rightangle from the position shown in Fig. 1, until the pin ends strike the inner vertical boundaries of the portions 19", so that each projecting end of the pin 1 8 is aligned with the vertical portion 19", and thus, although the spring 9 urges the plunger 8 into the fully closed position illustrated in Fig. 2, the button 1 2 can be manually depressed to adjust the valve over its full range of opening, but release of the button 1 2 immediately enables the spring 9 to return the plunger 8 to its fully closed position, in which each projecting end of the pin 1 8 strikes the uppermost boundary of the portion 19".

In Fig. 3, the valve closure plunger 8 is seen latched in a partly open condition. To achieve this the plunger has not only been depressed to an extent sufficient to allow the bore 5 to communicate partly, preferably to an extent of half of the fully open flow rate, with the bore 6, but the knob 1 7 has been turned through approximately another halfright-angle to bring the projecting ends of the pin 18 into the portions 19'. In the condition shown in Fig. 3, the projecting ends are resting on the respective uppermost boundaries of the portions 1 9', and thus the button 1 2 can be released without the plunger 8 returning to its closed condition.However, if desired, the degree of opening of the valve can still be adjusted up to its fully open condition against the action of the spring 9, any release of the button 12 automatically enabling the spring 9 to return the plunger 8 to its half-open condition.

In the condition shown in Fig. 4, the plunger 8 has been depressed into its fully open condition and the knob 1 7 turned through approximately a further half-right-angle to bring the projecting ends of the pin 18 to directly beneath the lower end faces of the part 3. In this condition, the plunger 8 is latched in its fully open condition.

The pin 1 8 can be formed of polypropylene and can be so designed as itself to shear, rather than have the lower end of the part 3 shear, if the plunger 8 is pressed excessively strongly downwards in the condition shown in Fig. 1. The pin 1 8 is removable for replacement after such shearing, and also for cleaning and maintenance of the valve. For this latter reason, the plunger 8 is preferably made in two parts received axially one within the other and interconnected by only the pin 1 8.

In use of the sprayer incorporating the valve, it is easy to bring the valve into the condition shown in Fig. 1, it being simply necessary, after release of the button 12, to rotate the knob 1 7 clockwise until the projecting ends of the pin 1 8 abut the closed ends of the portions 1 9"'.

Claims

1. A manually operable fluid-flow control valve comprising a housing, a valve port in said housing, a valve closure member manually movable between a closed condition in which said member closes said valve port and an open condition, biassing means urging said member in the direction from said open condition to said closed condition, and latching means which can be manually rendered effective and ineffective to maintain said member latched in said open condition against the action of said biassing means.

2. A valve as claimed in claim 1, wherein said open condition is a partly-open condition.

3. A valve as claimed in claim 2, wherein said member is manually movable among said closed condition, said partly-open condition and a fully-open condition, said direction is also the direction from said fully-open condition to said partly-open condition, and said latching means can be manually rendered effective and ineffective to maintain said member latched in said fully-open condition against the action of said biassing means.

4. A valve as claimed in any preceding claim, wherein said closed condition includes a first closed position in which said member is prevented from performing an opening movement against the action of said biassing means and a second closed position in which said member may perform an opening movement against the action of said biassing means.

5. A valve as claimed in any preceding claim, wherein said latching means can be manually rendered effective and ineffective as aforesaid by turning one part of said latching means relative to another part thereof about an axis.

6. A valve as claimed in claim 5, wherein said one part comprises a projection and said other part comprises stepped means on which said projection can abut at a plurality of levels.

7. A valve as claimed in claim 6, wherein said stepped means comprises a recessed end surface of said housing including one or two recess base surface portions which said projection abuts in the open condition or the respective open conditions.

8. A valve as claimed in claim 7, as appended to claim 4, wherein said stepped means also includes a recess undercut surface portion which said projection abuts in said first closed position.

9. A valve as claimed in claim 8, wherein said projection is designed to shear in the event that its abutting pressure against said undercut surface portion becomes excessive.

10. A valve as claimed in any preceding claim, wherein said member comprises a manually depressable plunger reciprocable within said housing among said closed condition and said open condition(s).

11. A valve as claimed in claim 10 as appended to claim 5, and further comprising a setting knob fixed to said plunger and manually turnable to turn said one part of said latching means as aforesaid.

12. A valve as claimed in claim 11, and further comprising a button fixed to one end of said plunger and arranged to abut said housing to limit manual depressing of said plunger, said knob being fixed to the opposite end of said plunger.

1 3. A valve as claimed in claim 10, 11, or 12, as appended to claim 6, wherein said projection is part of a pin removable from said plunger.

14. A valve as claimed in claim 13, wherein said plunger is in first and second parts interconnected by said pin.

15. A liquid-flow control valve, substantially as hereinbefore described with reference to the accompanying drawings.

1 6. in a horticultural sprayer, a valve as claimed in any preceding claim.