WO2001026866A2

WO2001026866A2 - Improved air or water hand held cleaning gun

Info

Publication number: WO2001026866A2
Application number: PCT/NZ2000/000199
Authority: WO
Inventors: Rodney William Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-13
Filing date: 2000-10-13
Publication date: 2001-04-19
Anticipated expiration: 2002-04-13
Also published as: WO2001026866A3; AU7973900A

Abstract

The object of the invention is to provide a compressed air or fluid cleaning gun with a simple valve that allows a larger medium flow, a fine progressive control, and a cleaning gun that will cope with rough service. The construction of this cleaning gun is a pistol shaped body (1), a flexible hose (3), and a trigger assemble (2) that has a roller (4) fitted to serve as a pinch roller against hose (3) to stop medium flow while not in use. To operate, the trigger assembly (2) is simply drawn in towards the body (1) by finger pressure, which releases the pinch pressure from the flexible hose (1) and allows medium flow through the gun.

Description

Improved air or water hand held cleaning gun

Technical field

My invention relates to hand held cleaning guns for both industrial and domestic use where the cleaning medium used through the gun, can be compressed air or liquids. For example, water or water with cleaning or even abrasive agents.

In many cleaning operations and in particular, with air cleaning guns, there is a need to have a more powerful jet-stream of compressed air from the nozzle of the gun. This would provide a more rapid clean-up and remove unwanted particles and residues that may be partially adhered to the surface being cleaned.

Conversely, there are operations that require a positive control over the medium flow from the nozzle of the gun, to perform delicate cleaning tasks.

Background Art

There are many types of air or water cleaning guns in existence that tend to employ a conventional hand or finger operated valve, that serves to allow flow of medium from the nozzle of the gun as required. These conventional valves have some limitations as described below:

1. To be operated by hand or finger, the valve O'ring seal must be small in diameter and this leads to restricted flow of medium through the valve to the nozzle of the gun.

2. In operation there is a tendency to open and close suddenly, due to rapid deformation of the rubber O'ring seal, at the point of sealing or unsealing.

3. Leaking valve seal, due to foreign particles temporarily trapped between the O'ring seal and the valve seat.

Another aspect of air or water cleaning guns is the various problems that can occur due to rough treatment over time, while in service. For example, a cleaning gun that is regularly dropped on a concrete floor, may result in the external fixtures working loose and becoming lost or broken. O 01/26866

Disclosure of invention

In accordance with the present invention, I provide a hand held cleaning gun consisting of a pistol shaped body, a flexible hose and a pinch roller which is mounted within a trigger assembly, The flexible hose, which carries the air or liquid medium to the nozzle, is also one component of the valve that controls the flow of medium to the nozzle. The pistol shaped body which houses the hose, has a flat rear wall as a second component of the valve. The third component of the valve, is the pinch roller, mounted within the trigger assembly, that operates on a pivot point within the body. When the valve is closed the pinch roller has the flexible hose pinched against the flat wall at the rear of the body. When the trigger assembly is operated, the pinch roller moves away from the flat wall of the body, allowing the point of pinch on the hose to open and allow medium to flow through to the nozzle of the gun.

This invention can now be described by way of reference to the accompanying drawing 1, where FIG.1. shows one possible configuration of a hand held cleaning gun, hereinafter referred to as the "gun", employing the above described valve mechanisms and where FIG.2. shows a cutaway, open view of the above described valve mechanism.

The construction of this gun begins with a length of flexible hose (1-3) of suitable material that can be neatly fitted inside a pistol shaped body (1-1) made from a suitable durable material. At the bottom of the body (1-1), one end of the flexible hose (1-3) could protrude and have fitted to it, a standard air or water hose half coupling (1-12) to facilitate the use of standard compressed air or fluid hoses and connections.

At the top forward end of the gun, the other end of the flexible hose (1-3) could protrude well passed the end of the body (1-1) to provide a flexible overhang (1-13). This flexible overhang can serve as an almost indestructible connection point, to where a nozzle (1-14) or any other special attachments can be fitted. One example of special attachments could be a venturi nozzle for a medium, where particles could be drawn into the venturi and into the jet-stream from the nozzle (1-14).

The control valve for this gun could be an "L" shaped trigger (1-2) where the long side of the "L" shape could become the finger grip region of the trigger. The bottom right angle corner of the "L" shape, could be where the trigger (1-2) pivots on pivot axle (1-6). At the far end of the "L" shape, a roller (1-4) could be fitted. This roller could serve as a pinch roller to flatten the flexible hose (1-3) against the flat area between (1-7) and (1-8).

When operated, the trigger assembly (1-2) can be drawn into the body (1-1) in the direction of arrow (1-10) by the operators fingers. The pinch roller (1-4) will roll down and swing slightly away from the flexible hose (1-3). This will release the pinch pressure and allow medium to flow through the gun. O 01/26866

-3-

The amount of flow through the gun can be easily controlled by how far the trigger assembly (1-2) is drawn into the body (1-1) by the operator. A strong return spring (1-9) can be shaped at one end to fit neatly within the body (1-1) and wound several times around pivot (1-6) and where the other end of the spring (1-9) can lay concealed inside the trigger assembly (1-2). Spring (1-9) can serve to return the trigger assembly (1-2) back to the start position (1-7) to where the roller (1-4) can pinch firmly against the flexible hose (1-3) to stop the flow of medium. A small protrusion inside body (1- 1) could provide a mechanical stop (1-11) to ensure that roller (1-4) does not travel past the pinch point of body (1-1) at (1-7).

Unlike some control valves which have a tendency to open or close suddenly, the flexible hose and pinch roller concept offers a controlled flow of medium almost directly proportional to the amount of pinch pressure released from the flexible hose (1-3).

It could be seen from the above that this method of controlling medium flow through a cleaning gun could also provide a valve that can cope with rough service and foreign particles in the medium. If particles become trapped in the hose at the pinch point, these particles would tend to flush away when the cleaning gun was operated again.

Claims

The object of this invention is to provide a hand held cleaning gun that has improvements over existing cleaning guns and these are

1 To provide a control valve that will deliver a greater flow of medium to the nozzle of the gun

2 To provide a valve with improved control over the flow of medium through the gun

3 To provide a control valve that can cope with gas or liquid that is laden with solids (eg sand)

4 To provide a control valve with a very long service life

5 To provide a cleaning gun that can cope with rough service

It will be appreciated that some future changes may be necessary, without departing from the spirit or scope of this invention