GB1268365A - Improvements in or relating to vibratory apparatus - Google Patents

Abstract

1,268,365. Welding by pressure. AEROPROJECTS Inc. 28 March, 1969 [29 March, 1968], No. 55806/68. Heading B3R. In ultrasonic welding, a non-powered anvil 10 performs excursions out of phase with those of the vibrating sonotrode. An ultrasonic welding machine, which may be as disclosed in U.S. Specification 2,946,119, comprises a transducer coupling system terminating in a resonant sonotrode. An anvil assembly for use, e.g. with such a machine, comprises anvil 10 having a resonant frequency which differs from that of the sonotrode, being either above or below the resonant frequency of the latter. Anvil 10, which has a hardened face 10a which may be brazed or screw-attached to the anvil, is attached-preferably by brazing-to a base ring 12 which is detachably secured to a flange 18a of a mass 18 received within a support member 24 for attachment to the welding machine adjacent the sonotrode (Fig. 1, not shown). Elastomeric gaskets and 0-rings 20, 22, 26 and 28 prevent metal-to-metal contact between the mass 18 and the member 24. The length of the anvil 10, including the face 10a, is determined from the equation where: L is the length, in inches, of the anvil. K is the radius of gyration and equals r/2 of the anvil, where r is its radius. # is the angular frequency of the welding machine. C o is the velocity of sound in the anvil. α is one of the roots of the equation The diameter, d x , for anvils for use at any power level P x is determined from the equation and the first four roots α 1 to α 4 yield practical values of the anvil length and are α 1 # S#/4; # 2 # 9#/4; α 3 # 13#/4; α 4 # 17#/4.