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US 4,057,188 AGranted
Deep drawn plastic packing case with interlocking, hollow fastener projections
OwnerDieter Steinhardtinventor
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OwnerDieter Steinhardtinventor
Estimating the term…
A device for producing hollow, undercut projections on a packing case of thermoplastic sheet material in a deep drawing mold which comprises at least one projecting stem at whose free end a core having a laterally projecting nose may be pivoted around a transverse pin and is elastically supported against the action of a spring. The stem and core are covered by the heated plastic sheet during the deep drawing process to provide the undercut projection, and during the removal of the finished packing case the core is pivoted around its pin to a position in which its laterally projecting nose releases the undercut part of the projection on the packing. The hollow undercut projections on the packing case thus produced are hook shaped and a hollow shaft projecting from one of the packing halves changes to a hollow projection extending almost vertically from the shaft and in the locked position this projection intermeshed with a similar projection of a hollow shaft on the other packing half. Spacer projections are provided on the top side of each packing case half to abut with each other when the packing case is closed and they are in part undercut to prevent an intermeshing when the packing cases are slacked together.
A packing case produced of deep drawn plastic sheet material, comprising two halves joined by a web and provided with recesses for receiving appropriate goods, at least the edges of the two packing halves coming into contact one over the other during the locking of the packing case having hollow projections which are integral with the packing halves and intermeshing by pairs to constitute a locking part, the improvement consisting in that the hollow projections are hook shaped and a hollow stem projecting from the one packing half changes into a hollow nose projecting vertically from said stem and intermeshes in the locking position with a similar nose of a hollow stem on the other packing half.
Packing case consisting of deep drawn plastic sheet material consisting preferably of two halves joined by a web and provided with recesses for receiving appropriate goods, at least the edges of the halves coming into contact during the locking of the packing case comprising locking parts which are integral therewith and intermesh, spacer projections being provided with come into contact one above the other during the locking of the packing case, the height of the projections corresponding to the distance of the edges of the packing halves provided by the projections or by the height of the joining web between the packing halves, the improvement consisting in that at least some of the spacer projections are undercut so that an intermeshing of these projections during the stacking of empty packing cases is eliminated.
Dependencies are inferred from the claim text.