US3088626A - Shipping drum - Google Patents

Description

y 1963 o. J. VAN LEER ETAL 3,088626 CHRISTIAN RAGETTLI red States The present invention relates to shipping drums, and, more particularly, to a rneans -for reinforcing the end of the drum against harmonie oscillation.

During recent years the demand for relatively lightweight shjpping drums capable of withstanding the rigors of transportation has been increasing. Sueh drums, in the standard fiftyfive gallon size, are generally filled with a liquid material and transported via truck and/or railroad cars to either a point of consumption or storage.

long with increased demand for such drums has been the desire to reduce the costs of manufiacture and transportation of the drums. In an effort to overcome the weight and oost problems, manufacturers have followed a trend to thinner and lighter metal.

Shippers have been continuously plagued by drum failures resulting from metal zfatigue, particularly in tbat regon where the end member of the drum meets the side walls known as the "knuckle radius. Such metal fatigue and consequent drum ailure, bas been found to result from the localized bending -accompanying the harmonie oscillations which are reduced in the end member of a filled drum during transport. T he problem of drum-head harmonie oseillation has become increasingly vexing with the use of thinner and lighter metal stock.

The fatigue and -resulting fracture becomes a particularly serious problem When transportingh azardous material such as gasoline, corrosive liquid chemicals, and the like. Effor'os have been made to reinforce t-he drum ends,- for example, by going to special contours or by using a heavier gauge material. However, special oontours have not been particularly satisfactory, and any =appreciable increase in the thickness of the metal =adds to the cost and dead weight.

Accordingly, it is an object of this invention to provide a drum h=aving a renforced flat end member which is stronger than the end members conventionally employed. It is a more specific object to provide reinforcing means capable of minimizing drum-head harmonie oscillations during transportation of the drum. It isarelated object to provide a nevel reinforeing element capable of" minimizing harmonie oscillation and reducing vibrational flexure of a drum end member, which flexure results in metal fatigue.

It is another object to provide -an end member which facilitates staeking the drums in a straight stack and which makes it unnecessary for care to be exercised in alinng the drums with one another seam-to-searn. Cumulative cocking error is thereby minimized, neat st-acking is assured and risk of toppling is avoided.

It is a further object to provide a novel reinforcing means for use with shipping drum end members and which at the same time serves to distribute sharply concentrated forces over a wide area, thus reducing the unit stress to a level below that which will eause severe denting or puncturing. It is, therefore, an object to provide a drum having a bottom capable of resisting puncturing When the. drums are stacked on rough or uneven storage spaces, for example, in primitive oil producing areas.

It is another object to provide -an improved shipping drum. end member and reinforcing means therefor so as to allow the drum to be constructed from a lghter gauge ateit ice metal than Would otherwise be used, with a consequent saving in both oost and dead Weght.

These and -other objects and -advantages of this invention will become apparent upon reading the attaehed detailed deseription and upon reference to the drawings in which:

FIGURE 1 is a perspective view of an assembled shipping drum embodying the inven-ton;

FIG. 2 is an enlarged cross sectioi1 through one of the reinforeing cup members employed in accordance with the invention;

FIG. 3 is a section taken along the line 33 in FIG. 1 to bring out the height relationshipg according to the preferred embodiment of this invention;

FIG. 4 is -an end view of a shpping drum discldsing a modified form of a reinforcing member; and 7 FIG. 5 is a section taken alongthe lne 5+5 in FIG. 4.

While this invention has been described in connection with a preferred embodment, it will be understood that it is not intended to be iimited to this specifie embodiment, but rat-her to cover such equivalent and alterhative corrstruction as may be included withn the spirit and scope of the appended claims.

Referring to the drawing there is illustrated in FIG. 1 a shipping drum 11) having a cylindrical wall or body 11 which includes two or more spaced beads 12 to strengthen the drum and to facilitate rolling it. Secured to the bot tom of the drum is an end member 15 which is joined to the drum wall by a curled sea=m or chime 16. Concentration of the metal at the seam renforces the drum was a whole and permits it to be tipped =or -rolled on edge. Moreover, the seam 16 serves to transmit edgewise force to the drum wall When the drums are stacked in alinment, seam-to-seam'.

To form the seam the end member 15 isin the form of -a flat disk 13 having an upst-anding annular bead 20 (FIG. 3) about its periphery and defining an annular charinel 21 which engages one end of the cylindrical drum wall 11. It will be understood that after the drum wall 11 is seated in place within the channel 21, and as a subsequent manufacturing step, the two members are curled to'geth'er in overlapping relation to form the end seam 16. The flat central disk 18 is recessed with respect to the seam by"a predetermined depth -as indicated at d in FIG. 3.

It will be understood that When a shipping drum as hereinbefore described is being transportecl in the'filled condition, the bob-hing motion of the transportng vehicle is transmitted to the liquid withinthe drum. The liquid and resilient end member of the drum together form a resonant, oscillating system with the result th-at destructive harmonie oscillation is built u-p inthe drurnend member, even thoug-h the initiating vibraton is of low amplitude. When the oscillaton continues over a period of days the result is fatigue and fraeture, often wit-hleakageof the entire contents. The time required to produce thi's destructive effect in a shippingdnum is dependent on various factors such as the periodand ar1'uplitudeof the initiating vibration, the nature andhardness of the met'al as Well as its thiekness, and the density of the liquid being transported. Some understanding of the forces nvolved may be gained from the fact that a s hipping drum filled with water weighs approximately 500 pounds, the water being incompressible and co'nfinedso' that its full efiect is exerted on the thin bottom member.

In aecordance with one ofthe irriportant aspectsofthis in face-to-face contact over a substantial porton of the surface for inhibitng flexional vibration. In the preferred embodiment of this invention, three such reinforcing elements of channel cross section, here in tl1e form of cups 31, 32 and 33, have been employed and are aflixed to the end member in a two dimensional, triangular pat tern, as illustrated in FIG. 1. Of course, while three Such cups have been shown as afixed to the end member 15 in a triangular configuration, it will be understood that the particular number of reinforcing elements employed and the particular pattern in which they are arrayed may vary without departing from the invention. Moreover, the reinforcing elements may take other forms as illustrated in -FIG. 4 and to be discussed at a later point. While we have disclosed panticular forms of reinforcing members and particular configurations, it will be understood that the forms and configurations may be varied while still falling within the true scope and spirit of this invention.

Referring to FIG. 2, and in accordance With the preferred embodiment of this invention, a typical cup 31 has been illustrated. It will be noted that the cup 31 is of channel-like cross section having a base 35, and an up standing wall 36 which terminates in an outwardly extending fiange 37. The height of the cup indicated at a' is preferably constant over the entire area thereof and preferably equal to the height of the upstanding bead 20. Thus, the bottom portion 35 of the cup and the base of the bead 16 define a substantially flush supporting surface for the drum. 'I'he cup flanges 37, which extend over a substantial area of the flat disk portion 18 of the end member 15 in face-to-face contact therewith, are spot welded at spaced intervals to the bottom surface 19 thereof as, for example, indicated at 38 in FIG. 3.

While this invention has been descrbed in connection With a shipping drum having reinforcing elements secured to only the bottom end member thereof, it will be understood that the reinforcing elements may also be seeured to the top end member in a similar manner, thus allowing the drums to be stacked one upon another either upright or in inverted position.

In effect, the reinforcing cups form a plurality of boxlike protrusions which are rigidly secured to the bottom surface 19 of the end member. Analysis shows that the reinforcing elements serve several distinct functions.

First of all, the elements 3 1-33 serve as suppor-ting pedestals so that the weight of the contents is not diaphragm supported but rather transmitted directly to the underlying surface. But even when the reinforcing members are not in actual contact With a supporting surface the arrangement is beneficial since the extensive facetoface contact between the end member and the reinforcing elements, and the rgid nature of the latter, prevent the end member from acting as a vibrating diaphragm. Not only is the end member rigidfied but the period of natural vibration is changed so that it is no longer resonant under transport conditions.

Moreover, shipping drums employing reinforcing elements of channel-shaped cross section may be stacked upon one another to substantial heights without subjecting the bottom of the lowermost drum to localized puncturing stress resulting from irregularities and projections on the supporting surface. Such localized pressures can cause denting, weakening of the metal, or actual puncturing when eXer-ted against the bottom of a drum that is not equipped With reinforcing means of the type disclosed in this invention. However, by use of this invention, the bottom portions 35 of the cups in eifect serve as a double bottom and any concentrated pressure appled to one of the cups is distributed over a substantial area of the end member. Finally, the bottom portions 35 of the cups and the end seam 16 of the drum provide a substantially flush supporting surface which will enable the drums to be stacked one upon another without having to aline the drums seam-to-seam. Even when the drums are slightly offset from one another, the cups tend to keep the drums square and prevent them from cocking. Where the 4 drums are stacked in a plurality of tiers the cocking error tends to be cumulative and thus creates a toppling hazard. With the use of the present invention, the danger of toppling is minimized and neat and safe stacks are provided.

While the preferred embodimeut of this inventon contemplates the use of a plurality of fianged hollow cups, it will be understood that ether forms of reinforcing members may be used. For example, a single large cup may be used as set forth in FIGS. 4 and 5. Here the cup, indicated at 40, is axially centered With respect to the drum bottom 15a and has a diameter which is approximately one-third that of the drum itself. Encircling the cup is a flange 4-1 having a series of spot Welds 42 to the drum bottom. Preferably the cup is dished inwardly at the center for face-to-face contact over a limited area 43. This adds to the rigidity providing support about a circle M and enabling thinner metal -to be used than Would otherwise be possible. The advantages of the reinforcing member 40 are substantially the Same as is the earlier embodiment. Where the drums are stacked, and assuming that the disclosed reinforcement is used top and bottom, direct contact between the opposed reinforcing members is assured. Even thougl1 the drums may not be perfectly centered, the circles 44 are certain to intersect in direct supporting engagement. With regard to the bottom drum in the stack, this need not be seated on a perfectly flat supporting surface to get the desired supporting eiect; if only a portion of the circle 44 touches that is enough to prevent harmonic vibration. If, as may occur under some circumstances, part of the renforcing member is supported, the member still acts to rigidify the bottom to dampen any vibrations therein and thereby to efiectively inhibit any tendency toward oscillation. Thus, fatigue, and resulting rupture, are prevented under a1l pOS- sible conditions of use.

While the invention has been described in connection With preferred reinforcing elements having a height substantially equal to the height of the upstanding bead 20, there-by providing a substantially flush supporting surface, it will be understood that the supporting elements could have a slightly lesser height without departing from certain aspects of the invention.

Moreover, not only does the use of reinforcing elements secured to a shipping d1um end member serve to inhbit harmonic oscillations, to facilitate stacking and to prevent puncture and/or denting, but, as a net efiect, it enables shipping drums to be constructed of a thinner gauge metal With a substantial reduction in the initial expense of manufacture and a further reduction in the amount of dead weight that must be shpped. With the use of reinforcing elements of this nature, metal gauges as thin as 24- gauge in the case of a fifty-five gallon drum become practica1.

In our copending application Serial No. 807,517 filed August 20, 1959, now abandoned, a novel method of forming reinforcing cups from scrap and applying them to the end member of a shipping drum has been disclosed. Reinforcing elements used in the i1st embodirnent of the present invention may ideally be formed using the method disclosed in the aforesaid copending application.

It will be understood that our novel reinforcing means is not restricted to use With a perfectly flat end member, but rather will provide similar oscillation inhibiting characteristics, and is equally applicable when used With shipping drums having generally flat, i.e., slightly concave or convex end members, and it is this latter meaning which is intended in the following claims.

We claim as our invention:

1. A reinforcing member for use With shipping drums having a flat end member that is subjected to drum-head harmonic oscillations during transport, said reinforcing member comprising an extensive flanged support element having a channel-shaped cross section, said support element having its =flanges rigidly secured to said flat end member in face-to-face contact over a substantial area of the 1atter so that said drum-head harmonie osciiiatons will be dampened.

2. In combination with a shipping drum having a substantially flat end member that is subjected to drum-bead harmonie oscillations during transport, reinforcing means comprising at least one extensive flanged support element of channel-shaped cross secton, said support element rgid1y secured to said end member over a substantial area of the latter and having its flanges in face-to-face contact therewith so that said end member will be maintained in a substantially unflexed, relatively flat condition.

3. In a shippng drum, a drum wall, an end member in the form of a disk having a11 upstanding bead portion at its periphery defining a channel for engaging the drum wal1 and the upstanding bead portion further surrounding and defining a flat central portion, flanged reinforcing means rigidly secured to the fiat central portion of said disk and overlying a substantial portion of the area thereof with the flange in face-toface contact with the disk so that harmonie drum-head oscillations in said end member are substantially minimized during transport and so that the flat central portion of said disk is maintained in a substantally unflexed condition.

4. In a shipping drum, a drum wall, an end mernber in the form of a disk having an upstanding bead portion at its periphery defining =a channel for engagng the drum wa1l and with the upstandng bead portion further surroundng and defining a flat central portion, flanged reinforcing means rigidly secured in face-to-face contact to the fiat central portion of said disk over a substantial area of the 1atter, said reinforcing means having a height substantially equal to the height of said upstanding bead portion so that said upstanding bead portion and said reinforcing means define a substantially flush supporting surface and the flat central portion of said disk is restrained from harmonie oscillations during transport.

5. In a shipping drum, a drum wall, an end member in the form of a disk having an upstanding bead portion at its periphery defining a channel for engaging the drum wall and the upstanding bead portion further surrounding and defining a flat central portion, reinforcing means secured to the flat central portion of said disk for minimizing harmonic drum bead oscillations, said reinforcing means comprising a plurality of fianged support elements spaced from one another and having a substantially channel-shaped cross secton, said support eiements having their flanges Welded to the flat central portion of said disk to form a plurality of box-like protrusions on the latter, each of said support elements defining with said disk a doub1e bottom for protecting said end member against deformaton when the drum is placed on an irregular surface.

6. In a shipping drum, a drum wall, an end member in the form of a disk having an opstanding bead portion at its periphery defining a channel for engaging the drum wa11 and the upstanding bead portion further surroundng and defining a flat central portion, reinforcing means secured to the flat central portion of said disk comprising at least one holiow support element having a substantally channeI-shaped cross section and having flanges in face-tmface contact with and welded to a substantial portion of the area of the disk for minimizing harmonie drum-bead oscillations, said support element further having a height substantially equal to the height of the said upstanding bead portion so that said upstanding bead portion and said support element define a substantially flush supporting surface for protecting said end member against deformation when the drum is placed on an irregular surface.

7. In a shipping drum, a drum wa1l, an end member in the form of a disk havng an upstanding bead portion at its periphery defining a channel for engaging the drum walt and the upstanding bead portion further surrounding and definng a fiat central portion, oscillation inhibitng means secured to the fiat central portion of said disk for minimizing harmonic drum-head oscillations, said inhibiting means comprising a piurality of flanged metal cups secured at spaced points in a two dimensional pattern on said central portion and covering a substantial portion of the area of the latter, said cups havng their flanges in face-to-face contact with the metal of said disk and welded to the disk and said cups substantially equal to the height of the upstanding bead portion so as to form with said bead portion a substantially flush supporting surface for protecting (the end member against deformation when the drum is supported on an irregular surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,453,508 King May 1, 1923 1,715,782 Pickop June 4, 1929 2,730265 Lundgren Jan. 10, 1956 FOREIGN PATENTS 262,483 Italy Jan. 31, 1929

Claims (1)

1. A REINFORCING MEMBER FOR USE WITH SHIPPING DRUMS HAVING A FLAT END MEMBER THAT IS SUBJECTED TO DRUM-HEAD HARMONIC OSCILLATIONS DURING TRANSPORT, SAID REINFORCING MEMBER COMPRISING AN EXTENSIVE FLANGED SUPPORT ELEMENT HAVING A CHANNEL-SHAPED CROSS SECTION, SAID SUPPORT ELEMENT HAVING ITS FLANGES RIGIDLY SECURED TO SAID FLAT END MEMBER IN FACE-TO-FACE CONTACT OVER A SUBSTANTIAL AREA OF THE LATTER SO THAT SAID DRUM-HEAD HARMONIC OSCILLATIONS WILL BE DAMPENED.

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