AU2007234493B2 - Low vapour liquid applicators - Google Patents

Description

Australia Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT "Low Vapour Liquid Applicators" The following Statement is a Full Description of this Invention, including the best method of performing it known to me: 0 Background In many industries it is safe & prudent practice to minimise the exposure of workers to fumes from various solvents, cleaners, and adhesives used regularly in daily work activities. This is 5 the case in the plumbing trade in particular, where exposure to PVC cleaners and adhesives is associated with serious health risks over extended periods of use. At the present time, manufacturers of these solvents only supply a small brush attached to the lid of the solvent cement container for the use thereof; and supply nothing at all for the 10 application of priming fluid. The small brush for the solvent cement is very inefficient because of the low fluid retention aspects, usually resulting in dripping and loss of fluid when applying the solvent from the container to the PVC (Poly Vinyl Chloride) pipe joints. It also means that because of the rapid drying and absorption rate of the cement on the pipe joints, it often requires two workers working in unison to apply the cement to the joints, and in some cases 2 15 coats of the cement are needed to keep the fluid moist enough to push the joints together to their limit. This is especially so when the diameter of the pipes exceeds 100mm and in hot weather conditions. In the case of the priming fluids there is no applicator at all supplied, the instructions on the container advising the user to use a piece of rag for this purpose. 20 This inevitably results in fluid contact with the skin, and exposure to noxious vapours in the process. This method is repeated with every joint made, and unless the rag applicator is placed in a sealed container, the vapours are continually released into the atmosphere. Additionally, the rag dries out rapidly and requires frequent recharging using far more fluid in the process. With this in mind, low vapour liquid applicators have been developed and trialled 25 in various working situations in the plumbing trade to optimise the design and benefits of the applicators. Summary of Invention 30 According to one aspect of the present invention, there is provided a plumber's liquid applicator for applying liquid to join pipes or fittings, the applicator including: an elongate body including a handle and a stem extending from the handle; an absorber for mounting to the stem and for insertion into the liquid so as to absorb the liquid to be applied to the pipes or fittings; and 35 a seal for mounting to the body and able to be pushed into engagement within an opening of a container so that the absorber is sealed within the container. Optionally, the seal includes a tapered portion which engages with the opening. 40 Optionally, the tapered portion is resilient. Optionally, the seal includes a rubber collar which surrounds the body. Optionally, the absorber includes: 45 a tube for force fitting over the stem; and absorbent fabric for stapling to the tube. The applicator may further include the container which is a lid in which the absorber is contained. 50 Alternatively, the applicator may further include the container which contains a supply reservoir of the liquid. Optionally, the stem has a lesser cross sectional area than the handle.

Description Low vapour liquid applicators are made of materials resistant to the chemicals contained in the solvent cements and priming fluids used to join PVC (Poly Vinyl Chloride) pipes and 5 fittings. These chemicals are Methyl Ethyl Ketone and Acetone. Low Vapour Liquid Applicators in accordance with embodiments of the invention comprises a handle and stem made from Poly Propylene and manufactured in an injection moulding process (Figure 1). The stem is fluted to enable the synthetic fabric applicator (Fig 3 items 4 10 & 5) to be fitted thereon with a firm grip to it. The extended handle makes embodiments of the invention easier to use and more precise than the brush applicator supplied with the solvent cement containers currently in use. The synthetic fibre of the applicator is of a material commonly used on paint rollers, the difference 15 being that in the case of paint rollers the material is fixed to the central plastic core with adhesives in a spiral configuration. With embodiment of this invention, this is not possible because the chemicals contained in the fluids react with the adhesives over time and therefore lead to failure of the applicators. Because of this situation the fabric is stapled to a section of polyethylene tubing which is the pushed over the stem in a tight fit (Fig 3 items 4 & 20 5). The surface area of the fabric applicator is approximately 35 square centimetres, and a pile depth of 12 mm, compared with the surface area of the brush applicator supplied with the solvent cement containers of approx 5 square centimetres and a depth of 5mm. The handle 25 of the Low Vapour Liquid Applicators is fitted with a rubber seal (Fig 3 item 3). The purpose of this rubber seal is twofold: It enables the complete solvent cement applicators to be inserted into the solvent cement containers, forming an air-tight and fluid-tight seal, allowing neither fluid nor vapours to escape there from even when tipped over. The air-tight covers (Fig 2) also fit over the rubber seals and form an air-tight and fluid type seal when pushed onto the 30 tapered rubber seal allowing the applicators to be stored away from the containers when not in use. The applicators will not dry out for some considerable period of time when stored in this manner. For usage - Separate applicators will be used for the priming fluids (colour coded RED) and 35 the solvent cement fluids (colour coded BLUE). The priming fluid applicator is inserted into the priming fluid container and when all excess fluid has been drained back into the container with the aid of the sealed cap, is ready for use to prime the joints. The air-tight and fluid-tight cover is replaced onto the rubber seal of the 40 handle after each joint is primed prior to coating the joint with solvent cement. This process minimises the release of vapours, and prevents the fabric applicator from drying out in the process. At least 10 off 100mm pipe joints can be primed on one side before the applicator has to be recharged. 45 The solvent cement applicator is charged by directly inserting into the solvent cement container and is continually used there from. The applicator may be stored in the solvent cement container, or can be removed and stored using the sealed cap. Sufficient fluid is retained on the applicator to easily coat both sides of a 150mm diameter PVC pipe joint without recharging. The fluid retention properties of the fabric applicator are such that a pipe 50 joint can be made horizontally or vertically without fluid spilling or dripping there from. In contrast, the brush applicator supplied with the solvent cement container holds a relatively small amount of fluid and has to be continually recharged to enable even joints down to 50mm diameter to be coated. 55 In tests, the brush had to be recharged approximately 16 times to enable a 150mm pipe joint 2 to be coated on both sides, and this required 2 workers to coat one side each of the joint simultaneously in order for the joint to be pushed together before the solvent cement was absorbed into the joint and dried out. In comparison, the Low Vapour Liquid Applicator required only one worker to do the same job, and was achieved in less time. Also, it is 5 impossible to hold a brush applicator when fully charged in a vertical 'brush-up' position without the fluid dripping down the stem. The extended handles of the Low Vapour Liquid Applicators (fig 1) can eliminate altogether the dangers of priming and solvent cement fluids coming into contact with the skin. 10 The anti-spill rubber seal on the top of the solvent cement container (Fig 3 item 7) prevents spillage of fluid down the container when the applicator is inserted and removed during use. Some points relating to embodiments of the invention "Low Vapour Liquid Applicators" are as 15 follows: 1. The handle and fluted stem of the Low Vapour Liquid Applicators (Fig 1) differ from the currently available methods of applying (by hand) priming fluids and solvent cements to PVC (Poly Vinyl Chloride) pipe joints. The extended handles allow the operators to 20 apply these hazardous fluids to pipe joints in a more precise manner, avoiding in the process the associated dangers of such fluids coming into contact with the skin. (refer page 2 lines 5 to 11) 2. The fabric applicators of the Low Vapour Liquid Applicators (Fig 3 items 5 & 5) have 25 been specifically designed for the use of applying priming fluids and solvent cements to PVC pipe joints. These fluids contain the chemicals Methyl Ethyl Ketone and Acetone. The fabric is stapled to a section of polyethylene tubing which is then pushed over the stem in a tight fit (Fig 1 item 2) as in point 1 above thereby avoiding the use of adhesives or epoxy resins to attach to the stem (which method inevitably 30 breaks down due to the aggressive nature of the chemicals involved. Refer page 2 lines 11 to 21) 3. The rubber seal (Fig 3 item 3) together with the handle as in point 1, and the fabric applicator as in point 2, form an air-tight and fluid-tight seal into the top of the fluid 35 containers (refer description reference page 2 lines 21 to 29) allowing the handle and stem as in point 1 and the applicator in point 2, and the rubber seal point 3 attached thereto to be used with the minimum wastage of fluids and release of hazardous vapours into the atmosphere. 40 4. The air-tight covers (Fig 2; description reference page 2 lines 25 to 29) together with the handle and stem as in point 1 and the applicator in point 2, and the rubber seal point 3 retain the fluids and vapours as described. 5. The anti-spill rubber seal on top of the solvent cement container (Fig 3 item 7; and 45 description reference page 3 lines 11 and 12) prevents the spillage of fluids from the solvent cement container. 3

Claims (9)

1. A plumber's liquid applicator for applying liquid to join pipes or fittings, the applicator including: 5 an elongate body including a handle and a stem extending from the handle; an absorber for mounting to the stem and for insertion into the liquid so as to absorb the liquid to be applied to the pipes or fittings; and a seal for mounting to the body and able to be pushed into engagement within an opening of a container so that the absorber is sealed within the container. 10

2. A liquid applicator as claimed in claim 1, wherein the seal includes a tapered portion which engages with the opening.

3. A liquid applicator as claimed in claim 2, wherein the tapered portion is resilient. 15

4. A liquid applicator as claimed in any one of the preceding claims, wherein the seal includes a rubber collar which surrounds the body.

5. A liquid applicator as claimed in any one of the preceding claims, wherein the absorber 20 includes: a tube for force fitting over the stem; and absorbent fabric for stapling to the tube.

6. A liquid applicator as claimed in any one of the preceding claims, further including the 25 container which is a lid in which the absorber is contained.

7. A liquid applicator as claimed in claim 1, further including the container which contains a supply reservoir of the liquid. 30

8. A liquid applicator as claimed in any one of the preceding claims, wherein the stem has a lesser cross sectional area than the handle.

9. A liquid applicator as claimed in any one of the preceding claims, further including a supply container in which a liquid reservoir is stored. 35 Robert Calvin Slade 27 April 2009 4