GB2217434A - Trigger devices for controlling a fluid valve - Google Patents

Abstract

A manually operated trigger device, primarily for pressurised garden sprayers has a body (1) through which fluid flows under the control of a valve (2) directly operated by a trigger (3) against a spring. The trigger has a pin (13) and a slot (11) connection to the body. With the pin (13) at one end of the slot (11) the trigger (3) can be pivoted clear of the valve (2), which can then be extracted and replaced. With the pin (13) at an intermediate position along the slot (11), the trigger (3) can be pivoted within limits defined by interengaging formations (16, 19) to turn the fluid flow on and off. With the pin (13) at the other end of the slot (11), the trigger (3) is either held on by interengaging hooks (8, 22) on body and trigger or off by the hooks having back-to-back engagement. <IMAGE>

Description

"Improvements relating to Trigger Devices for Controlling a Fluid Valve" This invention relates to trigger devices for controlling fluid valves. it is primarily intended for garden pressure sprayers in which the contents of a hand pumped pressurised container are discharged from a nozzle or lance at the end of a flexible tube. Where the tube meets the lance there is usually a valve to control the flow.

It is convenient to have this trigger-operated by a single finger or thumb of the hand holding the lance.

It is also desirable to be able to actuate the trigger to give very brief squirts, or generally to exercise fine control. At the same time it is also useful to be able to lock the trigger on and, when off, to prevent it being accidentally pressed on. These various modes require a versatile trigger mechanism.

The valve itself needs attention from time to time, for cleaning, replacement of washers or sealing rings, or for clearing an obstruction. A simple preferred form is a spool valve, and in one existing device this extends transversely to the general flow direction and has a plunger projecting at one end for operation by a trigger. At the other end, access to the valve is by a screw cap on a cylindrical housing projecting a substantial amount from the main body. When this is undone and removed, the spool valve and return spring can be dropped out. This is a "fiddly" business and, when removing the cap, there is always the danger of losing it, for it is small and rolls easily. It is also an extra part requiring manufacture and assembly time and expense.

It is the aim of this invention to avoid this and to use the trigger itself for the containment of the valve.

According to the present invention there is provided a trigger device for controlling a fluid valve, comprising a body through which fluid can flow, a spring-loaded valve member mounted in the body to control such flow, a trigger mounted externally of the body and co-operating with a projecting portion of the valve member to actuate the latter against the spring means, the trigger mounting enabling both pivotal movement and movement transverse to the pivot axis, and the body and the trigger having co-operable means which allow the trigger to be locked on or off, to be pivoted freely between a manually held on and an ordinary off position, and to be pivoted completely clear of the valve member, according to the adjustment of said transverse movement.

Conveniently, the valve member is a spool movable generally transversely to the direction of flow through the body. It will be removable when the trigger is pivoted completely clear thereof; otherwise, it is trapped by the trigger.

Conveniently, the trigger is coupled to the body by a pin and slot connection, the pivoting being about the pin and the transverse movement being lengthwise of the slot. Although it is preferred that the slot is in the trigger, and the pin is fixed to the body, the arrangement could be reversed. The connection will preferably be near the forward or discharge end, with the trigger extending back over the body.

Conveniently, the pin will be at one end of the slot when the trigger is on or off, at the opposite end of the slot for the pivoting movement clear of the valve member, and at an intermediate position along the slot for the free pivoting between on and off positions.

There will normally be direct transverse movement between the manually held on and locked on positions and between the ordinary off and locked off positions. Thus one locks the device on for example, simply by sliding the trigger while holding it on.

These locked positions are preferably determined by hooked formations on the trigger and body. They will interengage to hold the trigger in the on position and be in abutment to prevent the trigger moving to the on position.

There may also be interengaging formations on the trigger and body to limit the free pivoting between the manually held on and ordinary off positions. The interengagement is preferably such that transverse movement to a position from which the trigger can be pivoted completely clear of the valve member is possible only when the trigger is pivoted beyond a normal manually held on position.

For a better understanding of the invention, one embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an axial section of a fluid flow control body, Figure 2 is a side elevation of the forward part of the body, Figure 3 is a plan view of the forward part of Figure 2, Figure 4 is a section on the line IV-IV of Figure 2, Figure 5 is a section on the line V-V of Figure 2, Figure 6 is a side elevation of a trigger connectable to the body, Figure 7 is an underneath plan view of the trigger of Figure 6, Figure 8 is a front end view of the trigger, and Figures 9 to 13 show the complete trigger device, (the trigger of Figures 6 to 8 mounted on the body of Figures 1 to 5) in various states of operation.

The main components of the trigger device are a body 1, a spool valve 2 and a trigger 3. The rear end of the body, to the right in the figures but not shown in full, has a generally cylindrical but mostly corrugated grip 4, and a flexible hose is connectable into this by any convenient means. Forward of the grip there is a transverse valve housing 5 open at the top face 6 and terminating in a short downward extension 7. To the rear of and just below the top face 6, where it meets the grip 4, the housing has a detent 8. The spool valve 2 is slidable in this housing and is urged upwardly, towards the open end, by a coil spring 9 largely housed within the extension 7. The upper end of the spool valve 2 is rounded for rolling and sliding engagement with the underside of the trigger 3.

At the forward end of the body 1 there is a screwthreaded socket 10 into which a lance or nozzle (not shown) may be fitted. As will be evident from Figure 1, when the valve 2 is raised, communication between the hollow grip 4 and this socket is blocked, and when it is lowered (its upper end position then being shown by a broken line) there is a through passage.

The trigger 3 is an elongated member with a slot 11 in a central nose 12 at its forward end by which it is held captive to a pin 13 spanning mirror image lugs 14 upstanding from the socket 10, the nose 12 being a close fit between these lugs. The slot extends generally longitudinally of the trigger but is dog-legged downwardly at its rear end. The trigger can pivot about the pin 13, and it can also be slid longitudinally and slightly raised and lowered due to the contour of this slot.

The lugs 14 are extended rearwardly by parallel cheeks 15 which are flat on the inside but formed externally with ribs 16 along the upper edges and terminating near the rear ends in short downward portions 17. The trigger 3 also has lateral cheeks 18 immediately to the rear of the nose 12, and each of these have an inwardly projecting stud 19 at the forward lower end. These studs are engageable under the ribs 16 in a manner to be described.

The trigger's normally upper side (which will be the down side when the trigger is flipped up and forwardly) has a generally plain contour, but interrupted at about the mid length by an upstanding abutment 20. To the rear of this it falls away to a thumb or finger pad 21.

When pushing the trigger forwards, the abutment 20 provides a positive grip, and it can also be of assistance in pulling the trigger backwards.

On the underside, just to the rear of the abutment 20 and the cheeks 18 the trigger has a forwardly facing hook 22 for engagement with the detent 8.

The operation will be described starting from the Figure 9 position, which shows the trigger released. As mentioned above, it can be flipped forward in the direction of the arrow for full access to the spool valve 2, which may be occasionally necessary for replacement of seals or cleaning for example. This forward pivotal movement is only possible when the pin 13 is engaged with the forward end of the slot 11, with the trigger then being in its rearmost position with the studs 19 disengaged from below the ribs 16.

However, if the trigger is swung back, pushed downwardly to the full and then forwardly to the position of Figure 10, the pin 13 comes to the bend in the slot while the studs 19 pass under the rib portions 17. Releasing the trigger allows it to rise under the influence of the spring 9 acting through the spool valve 2 to the Figure 11 position, where it is limited against further upward movement by the studs 19 engaging the undersides of the ribs 16. The hook 22 is still clear to the rear of the top face 6 of the valve housing 5, and so free pivotal movement between the manually held on position of Figure 10 and the ordinary off position of Figure 11 is possible. However, if the operator wants to prevent this, the trigger 3 can be pressed further forwardly until the pin 13 engages the rear end of the slot 11.Doing this from the Figure 11 position brings the hook 22 over the top face 6 as shown in Figure 12 and the trigger is locked in the off position.

It cannot be pivoted up from there since the studs 19 are still firmly trapped by the ribs 16.

When the flow is turned on by the trigger being pressed down into the position of Figure 10, the operator may choose simply to hold it there so that there is instant control. Alternatively, he can slide the trigger 3 forward engaging the hook 22 in the detent 8 as shown in Figure 13. This holds the trigger down and on, and flow is continuous. Release is achieved by pulling back on the trigger and allowing the spring 9, acting through the spool valve 2 to push the trigger up, at the same time closing off the flow.

When pulling back from either the Figure 12 or the Figure 13 position, without undue downward pressure the studs 19 will engage the forward sides of the rib portions 17 and arrest the trigger. The trigger will have to be very fully depressed before the studs 19 can pass below the rib portions 17.

Claims (10)

1. A trigger device for controlling a fluid valve, comprising a body through which fluid can flow, a spring-loaded valve member mounted in the body to control such flow, a trigger mounted externally of the body and co-operating with a projecting portion of the valve member to actuate the latter against the spring means, the trigger mounting enabling both pivotalmovement and movement transverse to the pivot axis, and the body and the trigger having co-operable means which allow the trigger to be locked on or off, to be pivoted freely between a manually held on and an ordinary off position, and to be pivoted completely clear of the valve member, according to the adjustment of said transverse movement.

2. A trigger device as claimed in claim 1, wherein the valve member is a spool movable generally transversely to the direction of flow through the body.

3. A trigger device as claimed in claim 2, wherein the spool is removable when the trigger is pivoted completely clear thereof.

4. A trigger device as claimed in claim 1, 2 or 3, wherein the trigger is coupled to the body by a pin and slot connection, the pivoting being about the pin and the transverse movement being lengthwise of the slot.

5. A trigger device as claimed in claim 4, wherein the pin is at one end of the slot when the trigger is locked on or off, at the opposite end of the slot from the pivoting movement clear of the valve member, and at an intermediate position along the slot for the free pivoting between on and off positions.

6. A trigger device as claimed in any preceding claim, wherein there is direct transverse movement between the manually held on and locked on positions and between the ordinary off and locked off positions.

7. A trigger device as claimed in any preceding claim, wherein the locked positions are determined by hooked formations on the trigger and body being interengaged to hold the trigger in the on position and being in abutment to prevent the trigger moving to the on position.

8. A trigger device as claimed in any preceding claim, wherein interengaging formations on the trigger and body limit the free pivoting between the manually held on and ordinary off positions.

9. A trigger device as claimed in claim 8, wherein the interengagement is such that transverse movement to a position from which the trigger can be pivoted completely clear of the valve member is possible only when the trigger is pivoted beyond a normal manually held on position.

10. A trigger device substantially as hereinbefore described with reference to the accompanying drawings.