Method of manufacturing roller chimes for closed head drums

A method of manufacturing a closed hollow member, such as a closed head drum, formed of a thermoplastic material and having spaced end walls and at least one side wall extending between the end walls and with roller chimes extending radially outwardly from the side wall, comprising forming an openable and closeable hollow mold having spaced end surfaces and at least a side surface extending between the end surfaces, the end surfaces and side surface providing chime forming surfaces with a portion of the chime forming surfaces being movable in the direction between the end surfaces of the mold relative to the remaining portion of the chime forming surfaces of the mold and the spaced end surfaces and side surface defining a closed hollow space, positioning a tubular section of thermoplastic material within the mold in the opened state, closing the mold, applying a gaseous medium through the mold into the interior of the tubular section and blowing the thermoplastic material tubular section outwardly against the side and end surfaces of the closed mold and forming the end and side walls of the hollow member, and forming an annular, channel-shaped part in the side wall of the tubular section within the chime forming surfaces of the mold with the opening to the channel-shaped part directed toward the interior of the hollow member and the radially outer wall of the channel-shaped part projecting outwardly from the remainder of the side wall of the hollow member, wherein the improvement comprising the steps of:

• (a) forming an annular recess between the relatively movable chime forming surfaces of the mold,
• (1) said recess having an opening communicating with the channel-shaped part of the side wall of the tubular section of thermoplastic material;
• (b) displacing the movable chime forming surface relative to the remaining chime forming surfaces to press the channel-shaped part of thermoplastic material therebetween to at least begin formation of a first leg of an L-shaped chime extending radially outwardly from the side wall of the hollow member;
• and
• (c) squeezing a portion of the wall of thermoplastic material forming the channel-shaped part into the recess to form a second leg of the chime within the recess,
• (1) the opening in said recess having a dimension less than the thickness of the portion of the wall of the channel-shaped part squeezed thereinto, and
• (2) the second leg formed within said recess extending transversely from the outer end of the first leg generally in the same direction as the side wall of the hollow member and radially outwardly thereof.

A method of manufacturing a closed hollow member, such as a closed head drum formed of a thermoplastic material and having spaced end walls and at least one side wall extending between the end walls and with roller chimes extending radially outwardly from the side wall, comprising forming an openable and closeable hollow mold having spaced end surfaces and at least a side surface extending between the end surfaces, the end surfaces and side surface providing chime forming surfaces with a portion of the chime forming surfaces being movable in the direction between the end surfaces of the mold relative to the remaining portion of the chime forming surfaces of the mold and the spaced end surfaces and side surface defining a closed hollow space, positioning a tubular section of thermoplastic material within the mold in the opened state, closing the mold, applying a gaseous medium through the mold into the interior of the tubular section and blowing the thermoplastic material tubular section outwardly against the side and end surfaces of the closed mold and forming the end and side walls of the hollow member, and forming an annular, channel-shaped part in the side wall of the tubular section within the chime forming surfaces of the mold with the opening to the channel-shaped part directed toward the interior of the hollow member and the radially outer wall of the channel-shaped part projecting outwardly from the remainder of the side wall of the hollow member, wherein the improvement comprising the steps of:

• (a) forming an annular recess between the relatively movable chime forming surfaces of the mold,
• (1) said recess having an opening communicating with the channel-shaped part of the side wall of the tubular section of thermoplastic material;
• (b) displacing the movable chime forming surface relative to the remaining chime forming surfaces to press the channel-shaped part of thermoplastic material therebetween to at least begin formation of a first leg of an L-shaped chime extending radially outwardly from the side wall of the hollow member;
• and
• (c) squeezing a portion of the wall of thermoplastic material forming the channel-shaped part into the recess to form a second leg of the chime within the recess,
• (1) the opening into said recess being restricted relative to the thickness of the material to be squeezed therein to cause the plastic material to flow through said opening and into the recess, and
• (2) the second leg formed within said recess extending transversely from the outer end of the first leg generally in the same direction as the side wall of the hollow member and radially outwardly thereof.