Lidded drum

Abstract

A lidded drum of synthetic material includes a clamping ring of metal for fastening the lid on the upper drum rim, wherein the clamping ring is U-shaped in cross section and engages in the closed state with its upper leg over the lid rim and the lower leg engages under an annular contact surface of a border of the drum wall. The contact surface extends perpendicularly or obliquely relative to the longitudinal axis of the drum. The contact surface is arranged below the upper drum rim and constitutes the upper limitation of an indentation in the upper portion of the drum wall. The lid rim formed by an inner rim, an outer rim, and a connecting ring, has a U-shaped cross sectional profile which is open toward the bottom and includes a sealing bed for placing or foaming a lid seal therein, wherein the lid seal is pressed in the closed state of the drum lid by the clamping force of the clamping ring against the upper lid rim. An annular bead is integrally formed on the connecting leg of the upper and lower legs of the clamping ring, wherein the annular bead is directed radially inwardly and, when the clamping ring is closed, the annular bead rests in a positively engaging manner against the outer rim of the lid for securing the lid on the upper lid rim.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lidded drum of synthetic material with a clamping ring of metal for fastening the lid on the upper drum rim, wherein the clamping ring is U-shaped in cross section and engages in the closed state with its upper leg over the lid rim and the lower leg engages under an annular contact surface of a border of the drum wall which contact surface extends perpendicularly or obliquely relative to the longitudinal axis of the drum. The contact surface is arranged below the upper drum rim and constitutes the upper limitation of an indentation in the upper portion of the drum wall. The lid rim formed by an inner rim, an outer rim, and a connecting ring, has a U-shaped cross sectional profile which is open toward the bottom and includes a sealing bed for placing or foaming a lid seal therein, wherein the lid seal is pressed in the closed state of the drum lid by the clamping force of the clamping ring against the upper lid rim.

2. Description of the Related Art

In lidded drums of this type as known from U.S. Pat. No. 5,301,853, the sealing effect of the drum lid is effected by an axial pretensioning of the lid seal which is placed on the upper lid rim, wherein the axial pretensioning force is produced during the closing of the clamping ring over the two inclined legs of the clamping ring which slide over the lid rim and the drum border. In lidded drums which are permitted to be used for storing and transporting dangerous liquids, certain demands are made with respect to the storage and transport safety which are tested by means of prescribed registration examinations, in which the lidded drums are subjected to a lateral drop onto the wall, a diagonal drop onto the lid rim, a static internal pressure measurement, and a stacking load.

In the lidded drum according to U.S. Pat. No. 5,301,853, the necessary strength of the ring is achieved by using a relatively great thickness of the sheet metal of the clamping ring, wherein, when the drum drops, for example, from the loading surface of a truck, leaks are prevented in the drum lid and, when the drum drops from a greater height, a separation of the lid from the drum due to deformations of the clamping ring are prevented. The disadvantages of this known lidded drum are the weight of the clamping ring because of the relatively large material thickness of the ring and the high price of manufacturing the ring.

SUMMARY OF THE INVENTION

It is the primary object of the present invention to further develop the lidded drum described above with respect to the tightness of the drum lid when the drum drops from middle or large heights.

In accordance with the present invention, the above object is met by providing an annular bead integrally formed on the connecting leg of the upper and lower legs of the clamping ring, wherein the annular bead is directed radially inwardly and, when the clamping ring is closed, the annular bead rests in a positively engaging manner against the outer rim of the lid for securing the lid on the upper lid rim.

The lidded drum of synthetic material according to the present invention with a clamping ring of metal for fastening the drum lid on the upper drum rim has compared to the known lidded drums the advantage of an improved strength with respect to drops and a clamping ring with reduced material thickness leading to the reduction of the weight of the clamping ring and to a reduced manufacturing cost of the clamping ring because of a reduced use of material.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is an elevational view of the lidded drum; and

FIGS. 2 and 3 are sectional views, on a larger scale, showing portions of the upper area of the lidded drum with two different embodiments of the clamping ring closure of the drum lid.

DETAILED DESCRIPTION OF THE INVENTION

The lidded drum 1 manufactured of synthetic material as shown in FIG. 1 is composed of a drum wall 2, a lower bottom 3, a drum lid 4, as well as a clamping ring of metal for fastening the lid 4 on the upper drum rim 6.

In both embodiments of the drum illustrated in FIGS. 2 and 3, the clamping ring 5, which has a U-shaped cross sectional profile, engages with its upper leg 7 over the lid rim 8 and engages with its lower leg 9 on the annular contact surface 11 of a border or projection 12 at the drum wall 2, wherein the annular contact surface 11 extends obliquely relative to the longitudinal axis 10 of the drum, and wherein the border 12 is arranged underneath the upper drum rim 6 and forms the upper limitation of an indentation 13 in the upper portion of the drum wall 2. The drum rim 8 formed by an inner rim 14, an outer rim 15, and a connecting ring 16 has a downwardly open U-shaped cross sectional profile with a sealing bed 17 for placing or foaming a lid seal 18 therein, wherein, in the closed state of the cover 4, the lid seal 18 is pressed as a result of the clamping force of the clamping ring 5 against the upper drum rim 6.

In the first embodiment illustrated in FIG. 2 of a clamping ring closure of the drum lid 4, an annular bead 20 is integrally formed on the connecting leg 19 of the upper and the lower legs 7, 9 of the clamping ring 5, wherein the annular bead 20 is directed radially inwardly and, when the clamping ring 5 is closed, the annular bead 20 engages in an engagement groove 21 formed in the outer rim 15 of the lid 4 for securing the lid on the upper drum rim 6.

When the lidded drum 1 is dropped from a height onto the lid rim 8, the clamping ring 5 is upset and the annular bead 20 of the clamping ring is pressed into the engagement groove 21 in the outer rim 15 of the lid rim 8. In this manner, the drum lid 4 is better secured on the drum rim 6 and the strength of the drum with respect to drops is increased, such that the material thickness of the clamping ring can be reduced.

The second embodiment of the clamping ring closure of the drum lid 4 according to FIG. 3 is characterized in that, when the clamping ring 5 is closed, the annular bead 20 engages on the upper drum rim 6 against a support ring 22 integrally formed on the outer rim 15 of the lid for securing the drum lid 4 on the upper drum rim 6.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

1. A lidded drum of synthetic material comprising a clamping ring of metal for fastening a drum lid on an upper drum rim, wherein, in a closed state, a clamping ring having a U-shaped cross section engages with an upper lid thereof over a lid rim, and engages with a lower leg under an annular contact surface of a border of the drum wall which extends perpendicularly or obliquely relative to a longitudinal axis of the drum, wherein the annular contact surface is arranged under the upper drum rim and forms an upper limitation of an indentation in an upper portion of the drum wall, and wherein the lid rim formed by an inner rim, an outer rim, and a connecting ring, has a downwardly open U-shaped cross sectional profile with a sealing bed for placing or foaming a lid seal therein, wherein, in the closed state of the drum lid, the rim seal is in the closed state of the drum lid pressed against the upper drum rim by the clamping force of the clamping ring, further comprising an annular bead formed on the connecting ring between the upper and lower legs of the clamping ring, wherein the bead is directed radially inwardly and, when the clamping ring is closed, the annular bead engages positively on the outer rim of the lid for securing the lid on the upper drum rim.

2. The lidded drum according to claim 1, wherein the outer rim of the lid has an engagement groove for the annular bead of the clamping ring.

3. The lidded drum according to claim 1, comprising a lower support ring for the annular bead of the clamping ring which acts on the support ring, wherein the support ring is integrally formed on the outer rim of the lid rim.