Abstract: The method of ultrasonic inspection of welds of articles, wherein planes (3, 8) of polarization of transverse ultrasonic oscillations radiated into a weld (4) of an article (2) and of these oscillations registered upon their reflection by the reflecting surface of a flaw (6) of the weld (4) are set relative to each other at an angle 2.delta., an angle .xi..sub.1 between the plane (3) of polarization and a plane (5) of incidence of ultrasonic oscillations upon the reflecting surface and an angle .xi..sub.2 between the plane (8) of polarization and the plane (5) of incidence being selected substantially equal to 70.degree., thus providing for extracting from the radiated ultrasonic oscillations their component polarized horizontally with respect to the reflecting surface of the flaw (6), the amplitude of which is employed to estimate the geometrical parameters of the flaw (6), while the time of its registration is used to estimate the location of the flaw (6) in the weld (4).

Abstract: A bioprosthetic heart valve comprising a biological transplant on a frame nsisting of a supporting ring with struts extending therefrom over a toroidal surface and connected with said ring by arcuate portions of an additional ring, a covering made from a biologically inert material with an isolation spacer, which form a toroidal envelope, the biological transplant secured to the covered-up frame having envelopes shaped like aortic sinuses, joining smoothly the cusps whose number corresponds to the number of envelopes; a method of preparing the biological transplant from the aortic valve of an animal or human being comprising the dissection of the aortic root with aortic valve and cutting out a transplant with cusps, fibrous ring and aortic sinuses from a flap of biological tissue with the aid of a device comprising a punch and two matrix plates, said punch being made in the form of a plate with projections and bulges thereon, entering the cutouts on the matrix plates, and a method for preparing the biological

Abstract: A press comprises a frame made up of two crossheads rigidly interconnected y means of uprights with two rams mounted therebetween one above the other. One of the rams has a built-in nut with a non-self-stopping thread to be thereby engaged with a screw rigidly connected to a die holder mounted for rotation in the other ram and geared to a drive for its translatory motion. Forced interaction between the nut and the screw is effected through a drive provided to actuate the ram with the nut and controlled from the drive of the die holder. There is provided a clearance of sufficient size between the rams to permit a specified angle of rotation of the die holder.

Abstract: A press comprises a frame made up of two crossheads rigidly interconnected y way of uprights with two rams mounted therebetween one above the other. One of the rams has a built-in nut with a non-self-stopping thread to be thereby engaged with a screw rigidly connected to a die holder mounted for rotation in the other ram and geared to a drive for its translatory motion. Forced interaction between the nut and the screw is effected through a drive provided to actuate the ram with the nut and controlled from the drive of the die holder. There is provided a clearance of sufficient size between the rams to permit a specified angle of rotation of the die holder.

Abstract: A method and apparatus for lapping workpieces or components. A planetary-type plane lapping machine has a stationary lapping disc and a rotary driven rotary lapping disc. A cage having a socket for holding work to be lapped is disposed between the stationary lapping disc and the rotary lapping disc. The cage is a planet gear driven by a sun gear and a ring gear of a sun-and-planet gear. A differential gear train couples the sun gear with the rotary disc for driving the rotary lapping disc and a differential mechanism controls the direction of wear of the working surfaces of the lapping discs. In order to carry out the method disclosed the rotary lapping disc is driven rotationally at substantially twice the speed at which the center of the cage rotates about the axis of rotation of the rotary lapping disc. This precludes the development of forces of the work being lapped from acting on the cage.