Abstract:
A plastic disposable canister for use with a conventional paint spray gun. The canister is a cylinder having a closed bottom, an open top, and two diametrically opposed external stiffening ribs extending the height of the canister. The canister includes two diametrically opposed cover engaging members formed from the upper portions of the stiffening ribs for engagement with the most commonly available paint sprayers.

Description:
This is a continuation of application Ser. No. 07/043,502, filed Apr. 28, 1987, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a universal plastic disposable canister to be used with spraying apparatus having a variety of different configurations. This invention is particularly suited for use with paint sprayers, although it is by no means so limited, and can be used with other sprayable liquids. 
     Paint sprayers which use metal canisters to hold the paint or lacquer to be sprayed are well known. The metal canisters are reusable and must be cleaned after every use, thereby increasing the time and labor of painting operations. In addition, it takes approximately a pint of solvent, e.g., paint thinner or turpentine, to clean a canister after every use. Solvents are considered hazardous waste and therefore must be disposed of carefully. These factors also add to the cost involved in the use of metal canisters with paint sprayers. 
     Disposable plastic containers for paint sprayers are known. See, e.g., U.S. Pat. No. 3,381,845. However, known disposable plastic containers are merely plastic copies of the metal container, using lugs projecting from opposite sides of the mouth of the container to engage a sprayer cover. They do not show the important features of the instant invention, explained in detail below. 
     SUMMARY OF THE INVENTION 
     The present invention is a canister molded of a plastic to include either high density polyethelene, high molecular weight polyethelene, polyvinylchloride or other suitable impact resistant plastic material. The preferred embodiment is a canister which is substantially cylindrical, having a closed base and one opening at the top typically having a diameter of approximately 3.472 inches. Ribs having dimensions approximately 0.100 of an inch wide and 0.125 of an inch deep protrude from diametrically opposing sides of the cylinder, and extend the vertical length of the canister from the base to the neck. At the neck, the ribs widen to form a rectangular opening which is reinforced on the upper portion by an angled extension of the rib. The rectangular opening is designed to receive hooked protrusions of a cover locking mechanism for a variety of paint sprayer apparatus. 
     The canister is preferably constructed by either extrusion blow molding or by injection molding of a plastic material and is designed to be used once and then disposed of. In addition, after the plastic canister is molded, the compression molded flashing which occurs at the seams, and which is normally trimmed away, is instead left on the canister to form strengthening ribs which reinforce the canister, enabling it to withstand the pressure applied to it when in use without collapsing. 
     Further, the wider top portion of the strengthening ribs, which protrudes from the neck of the canister, is shaped to form a rectangular opening with a reinforcing upper angled piece, also partly fashioned from the compression molded flashing. This angled piece enables the cover engaging means of the canister to withstand the full range of pressure that can be applied to it when sprayer covers are attached to the canister using these rectangular openings. 
     The distance between top of the rectangular opening and the lip at the top of the opening of the canister is approximately 0.529 of an inch. This distance was chosen so that there would be a sufficient depth to allow the plastic canister to be universally adapted to fit the three major types of sprayers presently on the market. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown. 
     FIG. 1 is a perspective view showing a seam with the flashing forming a strengthening rib. 
     FIG. 2 is an elevational view with the lower portions of the canister partially broken away. 
     FIG. 3 is a top plan view. 
     FIG. 4 is a sectional view taken along lines 4--4 in FIG. 2. 
     FIGS. 5, 8 and 10 are enlarged fragmented views of the upper portion of the canister showing the attachment of the three different major types of paint sprayer covers. 
     FIG. 6 is a sectional view taken along line 7--7 in FIG. 5 showing the cover in FIG. 5 in an unlocked position. 
     FIG. 7 is a sectional view taken along the lines 7--7 in FIG. 5 showing the cover in FIG. 5 in a locked position. 
     FIG. 9 is a sectional view taken along lines 9--9 in FIG. 8 showing the cover in FIG. 8 in a locked position. 
     FIG. 11 is sectional view taken along lines 11--11 in FIG. 10, showing the cover in FIG. 10 in a locked position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, wherein like numerals indicate like elements, there is shown in FIGS. 1 and 2 a plastic canister 10 having a top opening 14 and a closed base 15. The outer wall 20 of the canister tapers into a reduced diameter neck 12 with a lip 16. A strengthening rib 18, made from the flashing left after the compression molding process, projects from outer wall 20 and extends vertically upward conforming to outer wall 20. At the neck 12, the rib widens and is molded to form a rectangular hole 22. Strengthening rib 18 terminates close to the top of neck 12 with an upper angled projection 24, to reinforce and give added strength to the top portion 23 of rectangular hole 22. This angled projection 24 will enable the cover engaging means of canister to withstand the clamping pressure exerted on the upper portion 23 of rectangular hole 22 when a sprayer cover is secured in place. 
     FIGS. 3 and 4 show the top opening 14 and the closed base 15 respectively. 
     FIGS. 5 through 7 show the top portion of the canister 10 to which a conventional paint sprayer closure 26 has been attached. The closure 26 is manufactured by Binks, one of the three major companies in the paint sprayer business. The closure 26 comprises a cover 27 attached to a yoke assembly 28. The yoke assembly 28 has downward sloping arms 30. Each arm 30 of the yoke assembly 28 has a horizontal slot 32 near its end. The slot 32 allows the lower portion of the arm 30 to hook into rectangular hole 22. 
     Rotation of thumb bolt 34 lifts the yoke assembly 28 causing that portion of the arm 30 which is hooked into rectangular hole 22 to lift, thus applying pressure to the reinforcing upper angled projection 24, and at the same time forcing the cover 27 against the top of the canister 10 sealing it. 
     FIGS. 8 and 9 show the top portion of the canister 10 to which a conventional paint sprayer closure 26&#39; has been attached. The closure 26&#39; is manufactured by DeVilbiss, one of the three major companies in the paint sprayer business. The closure 26&#39; comprises a cover 27&#39; attached to a yoke assembly 28&#39;. The yoke assembly 28&#39; has downward sloping arms 30&#39;. Each arm 30&#39; of the yoke assembly 28&#39; has a horizontal slot 32&#39; near its end. The slot 32&#39; allows the lower portion of the arm 30&#39; to hook into rectangular hole 22. Rotation of the thumb bolt 34&#39; lifts the yoke assembly 28&#39; causing a portion of the arm 30&#39; which is hooked into the rectangular hole 22 to lift, thus applying pressure to the reinforcing upper angled projection 24 and at the same time forcing the cover 27&#39; against the top of the canister 10 sealing it. 
     FIGS. 10 and 11 show the top portion of the canister 10 which a conventional paint sprayer closure 26&#34; has been attached. The closure 26&#34; is manufactured by Sharpe, one of the three major companies in the paint sprayer business. The closure 26&#34; comprises a cover 27&#34; attached to a yoke assembly 28&#34;. The yoke 28&#34; has downward sloping arm 30&#34;. Each arm 30&#34; of the yoke assembly 28&#34; has a horizontal slot 32&#34; near its end. The slot 32&#34; allows the lower portion of arm 30&#34; to hook into rectangular hole 22. Rotation of the thumb bolt 34&#34; lifts the yoke assembly 28&#34; causing the portion of the arm 30&#34; which is hooked into the rectangular hole 22 to lift, thus applying pressure to the reinforcing upper angled projection 24 and at the same time forcing the cover 27&#34; against the top of the canister 10 sealing it. 
     As indicated, a particular advantage of the instant invention is its adaptability to each of the sprayer closures 26, 26&#39; and 26&#34;. In addition, it is sufficiently inexpensive to make so that it can be discarded when changing paint color or when a paint job is completed. This eliminates the time and labor involved in cleaning the conventional reusable canisters and eliminates the cost relating to the disposal of hazardous waste solvents. 
     The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.