CA2093243C - Plastic drum with drain sump and method of making the same - Google Patents

Abstract

A plastic drum is formed with a body having an access hole on top and protective chimes. The body also includes a sloping bottom with a sump aligned with the access hole to allow, substantially, all the contents of the drum to be removed without turning the body upside down.

Description

BACKGROUND OF THE INVENTION

This invention relates to a unitary plastic drum for shipping and storing various m~tPri~ls, and more specifically to a plastic drum for liquid m~tPri~l~, which drum has a sloping bottom with a sump so that all the liquid can be pumped out efficiently.
Plastic drums are used frequently to ship and store various materials. These types of drums are prefelled over metal drums because they are simpler and cheaper to make, easier to handle, and weigh less. Frequently, plastic drums are used to ship liquid m~tPri~l~ used in agriculture, or the chemical industry which are highly concentrated and therefore, must be diluted. Since these liquids are very expensive, it is iml)ol ~ that all the contents of the drum be removed before the drum is discarded or returned, to elimin~te waste. One method of emptying completely the contents of a plastic drum would be to turn the drum upside down.
However, this procedure is time-con~uming and requires special equipment. Moreover, if the drum contains hazardous m~tPri~l~, turning the drum over may result in a spill, which is both uneconomical and undesirable.
Hence, there is a great need in the art for a plastic drum which could be emptied efficiently.

SUMMARY OF THE INVENTION

In view of the above-mentioned disadvantages of the prior art, it is an objective of the present invention to provide a plastic drum which can be efficiently emptied without turning it over.

Yet a further objective is to provide a plastic drum which can be made efficiently and economically for example by blow molding.
Another objective of the invention is to provide a drum which can be emptied efficiently using standard equipment.
Other objectives and advantages of the invention shall become apparent from the following description of the invention. Briefly, a plastic drum constructed in accordance with this invention consists of a substantially cylindrical plastic body having a straight side, a top and a sloping bottom. At least one access hole is provided on the top for filling and emptying the drum, said hole being off-center. The bottom is formed with a sump which is vertically aligned with the access hole whereby as the drum is emptied, all the liquid collects in the sump and is easily removed. A top and a bottom chime are added to the body for protection as well as to ensure that the drum stands upright or vertical when resting on a horizontal surface, and to ease h~n-lling.
The invention herein comprises a blow molded plastic drum capable of being fully drained and emptied of its liquid contents, said drum comprising: a unitary plastic body including a side wall, an integral top and bottom with a center, said top having an access hole radially offset from said center, said bottom having a sump radially offset from said center and being vertically aligned and coaxial with said access hole, said bottom being sloped toward said sump so that liquid will flow along the sloped bottom into the sump, said sump having a base disposed below the sloped bottom and defining the lowest surface in said body so that the sump will receive liquid therein that flows from the sloped bottom, the area of the sump being relatively small compared to the total area of the bottom whereby all of the liquid in the drum will collect in the sump. A lower chime disposed around said bottom ~ ~, L~

2(a) and secured to said body in such a manner to have surfaces thereof below the sump so as to assure that the drum stands upright. An upper chime disposed around said top and secured to said body and having means to permit h~n(lling of the drum with mechanical means for h~n(lling the drum. A drain pipe having a top and bottom and extending from the access hole to the base of the sump with the bottom of the pipe being proximate the base of the sump and the top of the pipe adapted to be coupled with a pump for completely draining liquid from the sump and consequently the whole contents of said drum by suction.

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While the invention will be described in conjunction with illustrated embodiments, it will be understood that it is not intended to limit the invention to such embo lim~nte On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the drawings, similar features have been given similar reference numerals.
Referring now to the drawings, a drum 10 constructed in accordance with this invention includes a body 12 having a cylindrical sidewall 14, a top 16 and a sloping bottom 18.
Body 12 is made of a plastic material and is formed by blow molding. Sidewall 14 is formed with a pair of circumferential ribs 20, 22 which reinforces the body 12 and also facilitates handling the drum. Top 16 is formed with two circular access holes 24, 26 covered by suitable closures 28, 30. Holes 24, 26 are advantageously disposed away from the longituf1in~l axis of the drum so that it is easy to install and remove the closures, and it is easy to fill up and empty the drum.
A sloping bottom 18 is formed with a sump 32 defined by a flat area 34 joined to the rest of the bottom by a conical wall 36. Flat area 34 is circular and has a diameter which is slightly larger than access hole 26. Illlpo~ ly, area 34 is aligned vertically and coaxially with hole 26 and, as shown in Figure 1, defines the lowest area of bottom 18. Disposed on surface 34 is a boss 38. Extending between hole 26 and sump 32 is a draining pipe 40. At its top portion, draining pipe 40 is supported by access hole 26. Draining pipe 40 can be permanently installed within the drum, or it may be provided separately, and installed only prior to the ~ pen~ing of liquid thererroJIl. As shown in detail in FIGURE 1, draining pipe 40 includes an upper section 42, a sleeve 44 and a lower stub 46. Upper section 42 and stub 46 are axially movable within the sleeve 44 to adjust the overall length of pipe 40. In this manner the pipe 40 can be adjusted so its length matches exactly the inner height of body 12. The stub 46 is termin~ted with a bottom end 48 which is provided with perforations or holes (not shown) to provide a passageway for liquid from the sump to enter into the drain pipe 40. In this manner, the liquid from drum 10 may be dispensed for example by applying suction to pipe 40, or by other means well known in the art. Boss 34 is used to align the bottom of pipe 40 with respect to sump 32.
At, or near, the interface between sidewall 14 and top 16, there is provided a circumferential groove 50. This groove is used to hold a circumferential chime 52 disposed around the body 12. A similar groove 54 is used at the bottom of body 12 to hold a second chime 56. Chimes 52, 56 are used to reinforce and protect the body 12. More particularly, these chimes 52, 56 extend axially beyond closure 30 on top, or sump 32 on the bottom respectively, forming a disc-shaped p~u~e;led space. Chimes 52, 56 maybe made of plastic or a metallic material.
In addition, as mentioned above, bottom 18 is sloped. Chime 56 preferably has a uniform height and is mounted in such a manner as to ensure that drum 10 stands upright.
Without chime 56, drum 10 would tilt to one side and could not be stacked. Top chime 52 maybe provided with several small holes (not shown) to allow excess liquid to drain off from the side of the drum. In addition, chime 52 may be provided with several larger holes such a H. A chain or a rope maybe passed through these holes for lifting the drum 10. Chime 52 is also rimmed as at R to permit handling of the drum with a mechanical means such as by parrot beaks, lift truck forks or dNm buggies.
The drum is made by first, blow molding the body 12 to form a unitary structure, and then applying the chimes 52, 56 thereto. As mentioned before, pipe 40 may be inserted into the drum body either before shipping, or before dispensing of the liquid.
The drum described in the FIGURES is filled through one of the access holes, such as access 24. Although the other access hole 26 may also be used, access hole 24 is preferable because it permits the liquid to flow in much faster, while if hole 26 is used, the liquid flow will be impeded somewhat by pipe 40. Once the drum is filled, the closures are applied to seal the drum 10. The drum is stored or shipped as required. The liquid is dispensed, for example, by coupling drain pipe 40 to a suitable pump. I~ lly, bottom is sloping toward sump 32 so that surface 34 of sump 32 is the lowest surface within the drum, and since the area of the sump 32 is relatively small when compaled to the total area of bottom 18, at the end, substantially all the liquid in the drum is collected in sump 32 and may be easily removed thererrom.
Obviously numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.

Claims (9)

1. A blow molded plastic drum capable of being fully drained and emptied of its liquid contents, said drum comprising:
a) a unitary plastic body including a side wall, an integral top and bottom with a center, said top having an access hole radially offset from said center, said bottom having a sump radially offset from said center and being vertically aligned and coaxial with said access hole, said bottom being sloped toward said sump so that liquid will flow along the sloped bottom into the sump, said sump having a base disposed below the sloped bottom and defining the lowest surface in said body so that the sump will receive liquid therein that flows from the sloped bottom, the area of the sump being relatively small compared to the total area of the bottom whereby all of the liquid in the drum will collect in the sump;
b) a lower chime disposed around said bottom and secured to said body and having a uniform height so that when mounted it is assured that the drum stands upright;
c) an upper chime disposed around said top and secured to said body and having means to permit handling of the drum with mechanical means for handling the drum; and d) a drain pipe having a top and bottom and extending from the access hole to the base of the sump with the bottom of the pipe being proximate the base of the sump and the top of the pipe adapted to be coupled with a pump for completely draining liquid from the sump and consequently the whole contents of said drum by suction.

2. The drum of claim 1 wherein said drain pipe has an adjustable length.

3. The drum of claim 1 wherein said bottom further comprises a boss disposed on the base of the sump for vertical alignment of said drain pipe.

4. The drum of claim 1 wherein the base of the sump includes a flat surface and the sump includes a conical section joined to the base.

5. The drum of claim 1 wherein the flat surface and access hole are circular and the diameter of the flat surface is slightly larger than the access hole.

6. The drum of claim 1 wherever the top further includes a second access hole radially offset from the center of the top.

7. The drum of claim 1 wherein the upper chime includes a rim for lifting said drum.

8. The drum of claim 1 wherein the upper chime includes holes for lifting said drum.

9. The drum of claim 1 wherein said drain pipe has an adjustable length, said bottom further comprises a boss disposed on the base of the sump for vertical alignment of said drain pipe, the base of the sump includes a flat surface and the sump includes a conical section joined to the base, the flat surface and access hole are circular and the diameter of the flat surface is slightly larger than the access hole, the top further includes a second access hold radially offset from the center of the top, the upper chime includes a rim for lifting said drum, the upper chime includes holes for lifting said drum.