RICHARDS, Andrew, Anthony (59 Long Street West, Graceville, Queensland 4075, AU)
SCOTT, Jon, Robert (32 Erinvale Street, Oxley, Queensland 4075, AU)
RICHARDS, Andrew, Anthony (59 Long Street West, Graceville, Queensland 4075, AU)
| CLAIMS
1. A fluid applicator for application of a volatile or toxic fluid to articles inclusive of plastics pipes which includes:
(i) a base part including (A) means for attachment to a container of toxic or volatile fluid or (B) being integral with said container;
(ii) a tubular part integral with the base part having a hollow internal bore and a side wall which is permeable to allow egress of the fluid from the hollow interior to exit externally of the side wall wherein the internal bore has a diameter or transverse dimension which is 10 to 60% of the diameter or transverse dimension of the tubular part;
(iii) one or more layers of flexible material fitted over an external surface of the tubular part; and
(iv) a cap enclosing the tubular part and the layer of flexible material. 2. A fluid applicator as claimed in claim 1 wherein the base part has means for attachment to a container of the toxic or volatile fluid.
3. A fluid applicator as claimed in claim 1 wherein the base part is integral with the container.
4. A fluid applicator as claimed in claim 2 wherein the base part has a screw threaded portion which is attached to a mating screw threaded rim of the container.
5. A fluid applicator as claimed in any preceding claim wherein the tubular part has a plurality of apertures allowing egress of the toxic or volatile fluid from the hollow bore of the container and externally thereof so as to contact the layer(s) of flexible material.
6. A fluid applicator as claimed in any preceding claim wherein the tubular part has a single opening allowing egress of the toxic or volatile fluid from the hollow bore of the container and externally thereof so as to contact the layer(s) of flexible material.
7. A fluid applicator as claimed in any preceding claim wherein the cap is screw threadedly attached to the base part.
8. A fluid applicator as claimed in any preceding claim wherein the cap includes a deburring part for deburring a plastics pipe after it has been cut. 9. A fluid applicator as claimed in any preceding claim wherein the layer(s) of flexible material includes a sleeve of flexible material enclosing the tubular part.
10. A fluid applicator as claimed in any one of claims 1 to 8 wherein the layer(s) of flexible material include a plurality of discs of flexible material surrounding the tubular part. |
FLUID APPLICATOR
This invention relates to a fluid applicator for applying volatile or toxic fluid primarily to plastics pipes and in particular pipes made from polyvinyl chloride (PVC), chlorinated PVC (CPVC), polybutylene and ABS (acrylonitrile-butadiene-styrene copolymer). However the fluid applicator may be used to apply volatile or toxic fluid to other substrates as discussed herein. The fluid applicator however has specific relevance to PVC pipes and is concerned with jointing of PVC pipes.
In PVC joints which concern spigot-socket interaction between a male pipe and a female pipe there are many types of such joints which include (i) a male pipe functioning as a spigot which is inserted into an adjacent socket of an adjoining female pipe. There is also provided (ii) an elbow fitting which interconnects a pair of adjacent pipes wherein the elbow fitting may form a bend at right angles or at an acute angle such as 45°. In such joints the elbow fitting has a pair of end sockets in which each end socket is attached an adjacent end of an adjoining pipe which functions as a spigot. Conventional joints may also include (iii) slope junctions where an intermediate fitting has two end sockets and another socket extending at an acute angle to a conduit connecting the two end sockets. In each of the sockets an adjacent pipe may be inserted as a spigot. There is also provided (iv) another type of intermediate fitting which involves three sockets comprising two end sockets and a third socket extending at 90° to a conduit connecting the two end sockets. Again in each socket an adjacent pipe may be inserted as a spigot.
A conventional jointing procedure in relation to formation of joints inclusive of (i), (ii), (iii) and (iv) above includes the steps of:
(a) after the pipe has been cut which is to function as the spigot it is necessary to ensure that the pipe has been cut square or clearly and that all burrs have been removed from an internal surface and external surface by a suitable deburring tool which can also be used to roughen sharp edges. (b) ensure that the spigot is properly aligned within the adjacent socket and that an interference fit is achieved;
(c) dry, degrease and prime the spigot and socket with a lint-free cloth dampened with priming fluid which is usually methyl ethyl ketone.
Priming is extremely important as it etches off the gloss or oil from the PVC, and softens the PVC surface for later use of solvent cement;
(d) apply a solvent cement with a suitably sized brush to the internal surface of the socket and external surface of the spigot; (e) insert the spigot into the socket ensuring a well fitting interference fit; and
(f) allow the joint to cure over a period of 24 to 48 hours. A major disadvantage of the conventional method in forming a joint is that the priming fluid is primarily methyl ethyl ketone and this is highly volatile so that ignition will occur in the presence of a flame. The priming fluid is also toxic and hence contact with skin, eyes and mouth must be avoided at all costs. While conventional procedures ensure that it is necessary to wear gloves and effective eyewear such as safety goggles it will be appreciated that in some cases these safety procedures are not always followed. It will
also be appreciated that these procedures are not safety proof as the priming fluid vapour is heavier than air and will accumulate in trenches which are difficult to ventilate. Thus use of methyl ethyl ketone may lead to irritation of the eyes, nose and throat. Headaches and nausea may also occur. Another disadvantage of the conventional procedure discussed above is that the solvent cement used in step (d) above also has properties which are similar to methyl ethyl ketone and thus is highly volatile so that ignition may occur in the presence of a flame or other source of ignition. Damage can also occur to eyes, mouth and skin as the solvent cement is also toxic. Reference may be made to US Patent 7,125,189 which describes a fluid applicator having a side wall, a substantially closed first end defining an application surface and an open second end. A portion of the axial length of the applicator may be located around a duct which defines a passage in communication with a container configured to contain a product. When the applicator and container are coupled together at least one cavity is formed between a free end of the duct and an internal surface of the applicator. The product in the container may be dispensed from the container through the duct and onto the applicator by gravity.
To operate this fluid applicator it was necessary to apply the application surface to the desired substrate so that the applicator was in an inverted configuration wherein the product being dispensed by the fluid applicator such as a liquid or a powder passed through the application surface to contact the substrate. However this method of dispensing the product is inefficient and would result in flooding the substrate with product. It
would therefore not be suitable for dispensing a volatile fluid which is toxic in nature.
It is therefore an object of the invention to provide a fluid applicator which will make it possible to apply toxic or volatile fluids primarily, although not exclusively, to joints formed from plastics pipes where at least one spigot is to be inserted into at least one socket whereby damage to the skin, eyes or mouth is substantially reduced.
The fluid applicator for application of a volatile or toxic fluid to articles inclusive of plastics pipes which includes: (i) a base part including (A) means for attachment to a container of toxic or volatile fluid or (B) being integral with said container;
(ii) a tubular part integral with the base part having a hollow internal bore and a side wall which is permeable to allow egress of the fluid from the hollow interior to exit externally of the side wall wherein the internal bore has a diameter or transverse dimension which is 10 to 60% of the diameter or transverse dimension of the tubular part;
(iii) one or more layers of flexible material fitted over an external surface of the tubular part; and
(iv) a cap enclosing the tubular part and the layer(s) of flexible material.
The base part of the fluid applicator of the invention is attachable to the container of toxic or volatile fluid and this may be achieved by any suitable means inclusive of a male-female interaction involving a snap fit or interference fit or utilising a clamp. However most preferably use is made of
the base part having an internal screw threaded portion which is attached to a mating screw threaded rim of the container.
However it will also be appreciated that the base part may be integral with the container and thus be formed as a one piece plastics moulding. In some cases the container of fluid may form part of the applicator of the invention and in this regard the container may be specialised or be different to a normal or conventional container which contains the volatile or toxic fluid. Thus the specialised container may be adapted to fit a palm of a hand and may be made from resilient material so as to pressurise the contents. However in other cases the applicator of the invention may be attached to the normal or conventional container.
The tubular part is preferably round in cross section and thus forms a cylinder extending upwardly from the base part. However other cross sectional shapes such as polygonal may be used if required. The side wall of the tubular part is permeable to the toxic or volatile fluid and in a preferred arrangement has a plurality of apertures or a single aperture allowing egress of the toxic or volatile fluid from the hollow interior of the container and externally thereof of the tubular part so as to contact the layer(s) of flexible material. Preferably the layer or layers of flexible material are foam material being closed cell foam material such as polyurethane or polyisocyanate. Alternatively if the fluid is thicker or more viscous in the case of priming fluid such as solvent cement then the outer layer of flexible material may form a sheath or sleeve of fabric having flexible tines extending outwardly therefrom
or alternatively may have an open weave structure.
The cap is suitably attachable to the base part and this may be achieved in any suitable fashion, such as the cap being screw threadedly attachable to the base part or alternatively being attached to the base part by means of male-female interaction involving an interference fit.
Reference may now be made to a preferred embodiment of the invention as shown in the accompanying drawings wherein:
FlG 1 is an exploded view of one embodiment of the fluid applicator of the invention; FIG 2 is an assembled view of the fluid applicator shown in FIG 1;
FIG 3 is a perspective view of another embodiment of a fluid applicator of the invention;
FIG 4 is a sectional view of the fluid applicator shown in FIG 3;
FIG 5 is a sectional view of the fluid applicator shown in FIG 3 with the cap and flexible applicator material removed for the sake of clarity; and
FIG 6 is a sectional view of another priming fluid applicator of the invention.
In the drawings and in FIGS 1 to 2 reference is made to priming fluid applicator 10 which has a container 11 which contains priming fluid having body 12, neck 13 and threaded rim 14 surrounding open top 15, lower cap or base part 16 of applicator 10 having an internally threaded portion 17 which mates with threaded rim 14, intermediate threaded part 20 which is located outwardly of upstanding tube 18 having apertures 19, retaining plate 21, adsorbent sleeve 22 which fits over and surrounds upstanding tube 18 in use
as shown in FlG 2, top planar surface 23 which abuts or is adjacent retaining plate 21 in use as shown in FIG 2, and upper cap 24 having bottom flange 25, body part 26 and deburring part 27 having edges 28 and 29 sharpened for deburring a plastics pipe (not shown) after it has been cut. Cap 26 is also provided with a circumferential locating rib 30 which locates in corresponding recess 31. There is also provided aperture 32 in inner extension 33 of cap 16 to ensure an even or controlled flow of volatile or toxic fluid into hollow interior 34 of upstanding tube 18.
In use initially the plastics pipe is cut with a suitable cutting tool which may be a fine toothed saw, mitre box or circular saw with an abrasive disc. The pipe after being cut is to function as a spigot and thus must be insertable into an adjacent socket. All sharp edges should be deburred with deburring part 27 so that all burrs and swarf are removed. To ensure a full interference fit a 0.5mm chamfer may be imparted to the outer rim of the spigot. After deburring of the spigot and socket (if required) the priming fluid applicator 10 is then tilted so that the priming fluid is then passed from container 11 into upstanding tube 18 and is passed through apertures 19 onto adsorbent sleeve 22. The applicator 10 is then applied to a pipe joint wherein absorbent sleeve 21 contacts an external surface of the spigot and internal surface of the socket.
In another variation the absorbent sleeve 22 may be replaced by a sleeve having a plurality of spikes or flexible tines so as to resemble a brush. This will have relevance where the priming fluid is replaced by fluid of a thicker consistency or which is more viscous than priming fluid. A good
example of such a fluid is solvent cement.
It will be apparent from the foregoing that the applicator 10 of the invention is efficient in practice because volatile or toxic fluid flows through flow aperture 32 to ensure a controlled flow of fluid which gains access to absorbent sleeve 22. At all times cap 24 is maintained in a closing position preventing flow of fluid to the outside atmosphere except in use when the cap 24 is removed and applicator sleeve 22 is applied to the exposed surfaces of the pipe joint well clear of the eyes, mouth or skin when protective clothing is used. After use cap 24 is immediately attached to base part 16 to prevent any further risk of fluid obtaining access to the outside atmosphere.
FIGS 3 to 5 refer to another embodiment or example of a priming fluid applicator falling within the scope of the invention. FIG 3 shows an external perspective view of this embodiment showing applicator 10A with cap 40 and deburring blade 41 having cutting edges 42 which is located in notch or recess 43. Notch 43 is located in upwardly extending arcuate wall 44 of cap 40 which has a flat top wall 45. Cap 40 is provided with lower outwardly extending part 46 having gripping ribs 47. Cap 40 is screw threadedly engageable with base part 48 at 49 as shown in FIG 4. Base part 48 is integral with tubular part 50 having a single opening 51 extending through side wall 52. Base part 48 is also provided with external flat portions 39 adjacent knurled portions 38 which have vertical ribs 37. Tubular part 50 also has transverse rib 53 functioning as a retaining abutment for closure member 54 having stem 55 which locates in upper part 56 of inner bore 57 of tubular
part 50. Base part 48 is provided with screw threads 58 as shown in FIG 5 and downwardly and outwardly extending flange 60. Base part 48 also has internal screw threaded part 61 for engaging with corresponding threads on the neck of a hollow container (not shown). There is also provided chamber 63 below tubular part 50.
In FlG 4 there is shown a plurality of discs 62 surrounding tubular part 50 which are flexible or resilient in nature and thus may be formed from felt or other suitable material. These discs constitute one example of an applicator material or flexible layer(s) of material within the scope of the invention.
In FIG 6 there is shown another embodiment of the invention wherein the fluid applicator 10B is integral with a container of toxic or volatile fluid and in this embodiment there is provided container portion 70 having tubular part 71 and base part 72 which may be formed with container portion 70 as a one piece plastics moulding. There is also provided closure member 73 and opening 74. There also may be provided a cap (not shown) and a plurality of applicator discs (not shown). Container portion 70 may be in the form of a squeeze bottle as shown having opposed squeeze or flexible side walls 75. There is also shown inner bore 76 of tubular part 71. It will be appreciated from the foregoing that the fluid applicator of the invention is primarily designed to apply toxic or volatile fluid to joints formed from plastics pipes. However it will be appreciated that it can be used for application of volatile or toxic fluid to any suitable substrate, e.g. application of weedkiller to plants for example.