NZ201884A - Suction/blower device using compressed air blast - Google Patents

Description

20188 Patents Form No. 5.

Patents Act 1953 i 8 DEC No .201884 ^RECEIVED Date 10.9.1982 COMPLETE SPECIFICATION "Suction and Gas Blast Device" WE, ADDINGTON ENGINEERING LIMITED, a New Zealand company, of - 156 Hazeldean Road, Christchurch, New Zealand, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed,"to be particularly described in and by the following statement:-;/" J ;v. :-;-vv-;-v■■■-■■'■•■.■ 201884 The present invention relates to a device for providing both suction and gas blast facilities in a single tool, powered by compressed gas.

In industrial buildings, suction (i.e. vacuum cleaning) facilities normally are provided by electrically operated vacuum cleaners of known type, and gas blast facilities by compressed air from a compressor or from compressed-gas cylinders.

Known vacuum cleaners have the drawback of being unwieldy and bulky, and can be dangerous to use for collecting wet material. Since most industrial plants need gas blast facilities anyway, it would be convenient to power both gas blast 'and suction facilities from the same source, and this is one object of the present invention Commonly used gas blast facilities comprise a nozzle connected to the compressor or gas cylinder by. a hose. In use, the nozzle emits a jet of gas at the pressure of the compressor or cylinder, which pressure generally is extremely high. Such high pressure is not in fact essential for the majority of gas blast jobs, and can be very dangerous to the user, in that if the high pressure jet comes into direct contact with the skin over a vein, it can cause an embolism. A further object of the invention is to provide a gas blast facility which avoids this danger.

The present invention provides a device for providing both suction and gas blast facilities, comprising: a hollow barrel open at both ends; an eductor mounted on the internal wall of said barrel in communication with a gas-supply bore formed in said device, said eductor having a first position in 5 & A which gas supplied through said bore is directed in one direction \y ^ Ttie EJ>t/CTot IS Houwi K/i-ri-l/V THE WHEREBV ) along said barrel, and a second position in wjTtT'h/ga-s—6.up.p.. ' ' through said bore is directed in the other diJrection a 1 ong~sia±d-j r 2 90CTI5S5 received barrel.

Preferably, said eductor comprises an annular cross-section body having an internal shoulder formed with an annular aperture or with a plurality of holes, and the eductor is changed from said first position to said second position by reversing the eductor end-for-end relative to the barrel.

Preferably the device includes a trigger to switch on and off the supply of gas through the bore.

Most industrial gas-blast facilities use air as the compressed gas, and the present invention will be described with particular reference to compressed air. However, it will be appreciated that any suitable compressed gas could be used instead of air if desired.

By way of example only, a preferred embodiment of the present invention is described in detail with reference to the accompanying drawings, in which:- Fig.l shows a cross-section through part of a device in accordance with the present invention, with the valve in the 'suction' position; and Fig-.'2 shows a cross-section through the valve.

Referring to the drawings, a device 2 has the general shape of a small gun, with a circular-cross-section barrel 3 and a handle 4. The barrel 3 has a smooth inner surface adjacent each end 5, 6 and a recess 7 between these surfaces. The recess 7 accommodates an eductor 8 which.is formed with a circumferential shoulder. 9 at each end, in each of which an O-ring 10 is mounted, to form a gas-tight seal between the valve and the barrel.

Both ends 5, 6, of.the barrel 3 are tapered so that the internal diameter of the barrel increases_from the edges of the recess 7 outwards towards each end of the barrel i.e. the barrel with the eductor in place is in the shape of a Venturi tube. However, the device will operate satisfactorily (but less efficiently) with the barrel in the form of a straight-sided tube of uniform internal diameter.

The end 5 of the barrel is connected to the remainder of the device 2 by a screw-threaded connection 12 at one end of the recess 7, so that when the end 5 is removed, a user has access to the eductor 8 and can remove the eductor.

The handle 4 of the device is bored to provide a gas passage 13, the lower end of which is screw-threaded to receive the end of a compressed-gas hose. The handle also carries a trigger (not visible) which is connected to an on/off valve of known type, such that pressing the trigger opens the valve and allows gas from a compressed gas source to pass into the barrel of the device through the eductor 8.

The eductor 8 comprises an annular-cross-section body the internal surface of which provides two portions 15, 16 each with smooth internal surfaces. (The internal surface is the surface adjacent the internal surface of the barrel). The portion 16 is of uniform internal diameter, and lies flush with the adjacent barrel wall. The portion 15 is of tapered internal diameter, and increases in diameter from a diameter equal to that of the adjacent barrel wall to a diameter greater than the external diameter of the portion 16 by an amount equal to the diameter of a hole 18. A plurality of holes 18 are formed between said two portions 15 and 16. The free end of the portion 15 extends beyond the shoulder 17 at the free end of the portion 16 so that access to each hole 18 is through a passage 20 formed between the portions 15'and 16, and this passage 20 is".Tnclined at an acute angle to the longitudinal axis of the bore. The passages 20 open into a groove 19 which is in communication with the gas passage 13.

As an alternative (not illustrated) the holes 18 can be replaced by a single semi-continuous annular aperture, backed by an angled passage equivalent to passage 20. This alternative has the advantage of spreading the air entering the barrel through the passages 13, 20 and aperture, more evenly around the whole internal diameter of the barrel.

The fact that the or each passage 20 is inclined at an acute angle to the longitudinal axis of the barrel aids the efficient functioning of the device:- air emerging from the or each passage is directed forewards but partially into the stream of air moving along the barrel thus tending to mix with said air stream very thoroughly, and so inducts air into the barrel more efficiently than if the air emerged from the or each passage 20 either parallel to the barrel wall or perpendicular to said air stream.

The eductor 8 can be positioned in the recess 7 with the shoulder 17 facing the end 5 of the barrel (as shown in Fig.l) or with the shoulder 17 facing the end 6:- in the first position, the device is a suction device; in the second position the device is a gas-blast device.

The above-described device is used as follows:- an air-hose from a compressed air source is connected to the bore in the handle 4. When the trigger is pressed, with the eductor 8 in the position of Fig.l, compressed air passes throughthe on/off valve of the trigger, and through the holes 18 in the shoulder 17, in the direction indicated by"the single-headed arrows i.e. towards the end 5 of the barrel. The rush of air in this direction creates a low-pressure area in the end 6 of the barrel, and draws air and any loose material adjacent the end 6 into the barrel, to travel towards the end 5 as indicated by the double-headed arrows.-' Thus, the user simply points the end 6 of the barrel at loose material to be collected and presses the trigger, and the material is sucked into the barrel. A tube or bag is secured over the end 5 to collect the loose material sucked up by the device.

When the eductor 8 is reversed, air leaving the holes 18 is directed towards the end 6 of the barrel, and the device acts as an air-blast device.

It will be appreciated that air leaving the barrel at either end comprises a mixture of the high-pressure air from the compressed air source and air at atmospheric pressure drawn through the barrel by said high-pressure air. Thus, the air leaving the barrel is not at a dangerously high pres-sure, nor is it in a narrow jet.

MVf-uiL ',,,: v..": ' _ - - ■ 201S84

Claims (10)

WHAT WE CLAIM IS:

1. A device for providing both suction and gas blast facilities, comprising: a hollow barrel open at both ends; an eductor mounted on the internal wall of said barrel in communication with a gas-supply bore formed in said device, said eductor having a first position in which gas supplied ' through said bore is directed in one direction along said r. L. B. & A. yffowji (The gjfcian h Tvp.v&p P-wn/p n/rrmv barrel, and a s=ge-b±tw position in whichj^gas supplied through <£>S^So/%s' said bore is directed in the other direction along said barrel,

2. The device as claimed in Claim 1 wherein part of the barrel is removeably secured to the remainder of the barrel at a position adjacent the eductor and the eductor can be changed from said first position to said second position by removing said removeable part of the barrel, removing, reversing, and replacing said eductor, and replacing said removeable part of the barrel.

3. The device as claimed in Claim 1 or Claim 2 wherein the gas supply bore is provided with an on/off trigger.

4. The device as claimed in any preceding claim wherein the eductor is mounted at or near the mid-point of the length of the barrel and the internal diameter of the barrel increases gradually from the location of the eductor to each end of the barrel. - 7 ■'AS 2? OCT TO REcesv-

5. The device as claimed in any one of Claims 1-3 wherein the internal diameter of the barrel is constant along its length.

6. The device as claimed in any preceding Claim wherein the eductor comprises an annular cross-section body formed with an annular aperture in communication with both the gas-supply bore and the interior of the barrel.

7. The device as claimed in Claim 6 wherein said annular aperture is in communication, with the gas-supply bore only through a passage the longitudinal axis of which is at an acute angle to the longitudinal axis of the barrel.

8. The device as claimed in any one of Claims 1-5 wherein the eductor comprises an annular cross-section body formed with a plurality of spaced holes, each hole being in communication with both the gas-supply bore and the interior of the barrel.

9. The device as claimed in Claim 8 wherein each said hole is in communication with the gas-supply bore only through a. passage the longitudinal axis of which is at an acute angle to the longitudinal axis of the barrel.

10. A device for providing both suction and gas blast facilities, substantially as hereinbefore described with reference to and as shown in the accompanying drawings. ADDINGTON ENGINEERING LIMITED by their authorised agents: P.L.BERRY & ASSOCIATES Per: \\- T PATENT Of H">: | ' 8 DEC 19S3 & RECEiVi - 8 -