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US 4,482,421 AGranted
Ultrasonic friction-fusion method and apparatus
AssigneeSignode Corporation
InventorRonald W. Gurak
Life of this patent
Estimating the term…
Abstract
Apparatus and method for securing a thermoplastic strap around a package by compressing the overlapping strap end portions together and moving one of the overlapping end portions in a transverse direction relative to the other at a very high frequency and small amplitude to melt and fuse the interface region therebetween. The transducer used to produce the ultrasonic vibrations is supported solely at its nodal point where it is vibration free.
Claims4
Apparatus for securing a thermoplastic strap around a package or the like comprising:
- a support structure;
- means for placing a strap around a package and forming a tensioned loop having overlapped strap portions, an anvil reciprocably supported by said support structure, pivotally mounted ultrasonic means located on said support structure adjacent said overlapped strap portions, said support structure connected to said ultrasonic means solely at the nodal area of the ultrasonic means whereby it is supported in a vibration-free area relative to said support structure, said ultrasonic means including a tip portion having a side surface disposed adjacent said overlapped strap portions, means for effecting relative movement between said anvil and tip to compress the overlapping strap portions therebetween and means for operating said ultrasonic means to move said tip longitudinally and an adjacent overlapping strap portion at a very high frequency in a transverse direction relative to the adjacent overlapped strap portion to effect bodily sliding frictional movement between the overlapping strap portions to melt the interface regions therebetween.
Dependencies are inferred from the claim text.