Patent Publication Number: US-8973779-B2

Title: Drum

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation Application of U.S. patent application Ser. No. 11/316,225, filed Dec. 22, 2005, which claims priority of DE 10 2004 061 677.9-27, filed Dec. 22, 2004, the priority of these applications is hereby claimed and these applications are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to drums of thermoplastic synthetic material with a circumferentially extending carrying and transport ring arranged on the drum wall in the vicinity of the upper bottom, and at least one bunghole connection sleeve arranged in a trough-shaped indentation of the upper head of the drum in the area of the rim thereof. 
     The arrangement of the bunghole connection sleeve of the aerating and venting bung of a drum of the above-described type known from EP 0 287 966 A2 in the vicinity of the carrying and transport ring has the disadvantage that the bunghole connection sleeve is not protected even if arranged in a trough-shaped indentation of the upper head against external bending and compression forces which act laterally on the carrying and transport ring when the drum is dropped from a great height and which result in a deformation of the drum which inevitably has an effect on the bunghole connection sleeve of the aerating and venting bung. As a result, peak stresses may occur in the connection sleeve part and in areas adjacent this part which may lead to the formation of cracks and other damage, so that the tightness of the aerating and venting bung of the drum which is closed by a bung plug is no longer ensured. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to improve the resistance of the drum of the above-described type in the area of bunghole connection sleeve or sleeves against loads resulting from external force applications. 
     In accordance with the present invention, the above object is met by integrally forming a stiffening bead on the inner side of the carrying and transport ring of a drum of the above-described type in the vicinity of a bunghole connection sleeve as well as by forming a stiffening hump in the upper head of the drum between the stiffening bead of the carrying and transport ring and the bunghole connection sleeves. 
     As a result of the geometry of the upper area of the drum, the carrying and transport ring is reinforced in the area of a bunghole connection sleeve which, in the event of an external force application against the carrying and transport ring, prevents damage to the bunghole connection sleeve up to a certain strength of the force at which the carrying and transport ring is still not being deformed. A deformation of the carrying and transport ring when the expansion limit of the material of which the drum is manufactured is not exceeded when subjected to an external force application, is prevented by the stiffening hump in the upper head of the drum and the direct force application on the bunghole connection sleeve which would result in damage is prevented. 
     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 a perspective view of a drum according to the present invention; 
         FIG. 2  is a top view of a detail of the upper head of the drum, only larger scale, showing the filling and discharge bung; 
         FIG. 3  is a sectional view taken along sectional line III-III of  FIG. 2 ; and 
         FIG. 4  is a sectional view taken along sectional line IV-IV of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The drum  1  manufactured by extrusion blow molding from synthetic material is composed of a casing  2 , a lower bottom  3 , and an upper head  4  with a central stacking surface  5  and an outer carrying and transport ring  6 . 
     The upper head  4  of the drum  1  has two trough-shaped indentations  7 ,  8 ; diametrically oppositely located in the indentations  7 ,  8  are the bunghole connection sleeves  9 ,  10  of a filling and discharge bung  11  and of an aerating and venting bung  12 , wherein the connection sleeves are arranged recessed in the indentations  7 ,  8 . 
     An engagement groove  13  for a drum gripper extends between the carrying and transport ring  6 , on the one hand, and the stacking surface  5 , and the two indentations  7 ,  8 , on the other hand. 
     A stiffening bead  15 ,  16  each is integrally formed on the inner side  14  of the carrying and transport ring  6  in the vicinity of the bunghole connection sleeves  9 ,  10  of the filling and discharge bung  11  and the aerating and venting bung  12 , and two stiffening humps  17 ,  18  are formed from the bottom sections  19 ,  20  of the two indentations  7 ,  8  of the upper head  4  of the drum between the stiffening beads  15 ,  16  of the carrying and transport ring  6  and the bunghole connection sleeves  9 ,  10  of the two bungs  11 ,  12 . 
     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.