Abstract: A vibration motor comprising a rotor arranged within a cylindrical chamber having opposed radially arranged reciprocating pistons within cylinders opening into the chamber. Circumferential grooves formed in the rotor surface sequentially open the cylinders to a pressurized fluid outlet passageway, to move each piston outwardly, and to a fluid exit passageway to drain the cylinders for inward movement of the pistons. The pistons are axially aligned with and coupled to each other for producing rapid, low amplitude beam vibration. This is a division of application Ser. No. 898,905, filed Apr. 24, 1978, now U.S. Pat. No. 4,154,641.

Abstract: Vibration welding apparatus formed of a fixed frame supporting an elongated vibration beam and a vibration motor for rapidly vibrating the beam endwise along its longitudinal axis. Compression springs positioned between the beam ends and adjacent frame portions stop the vibratory movement of the beam upon stopping of the vibration motor. A vibratory platten is fixed to the beam, and a work-piece support platten is aligned with and movable towards and away from the vibratory patten. A pair of aligned thermoplastic work-pieces are squeezed together between the plattens for tight contact of the work-piece portions to be welded together. Actuation of the vibration motor causes melting of the contacting portions of the work-pieces due to frictional generation of heat. Stopping of the motor results in immediate realignment of the plattens holding the work-pieces in proper alignment for solidifying together.

Abstract: A method of welding together two thermoplastic surfaces to form a strong watertight bond therebetween comprising the steps of serrating the two surfaces while simultaneously melting the serrations formed therein and pressing the two surfaces together, ridge to ridge and valley to valley, to collapse the ridges and cause the molten thermoplastic material to flow into the valleys until a single continuous watertight seam is formed therebetween.

Abstract: Forming a joint in a thermoplastic strip by cutting a V-shaped notch in the strip, arranging a thin, heated blade within the notch and bending the strip about the apex of the notch for compressing the walls defining the notch against the blade for heating such walls, and then removing the blade and continuing the bending until the walls contact and join together. The notched strip is inserted between a pair of movable compression jaws, and the blade is mounted for reciprocating movement between and outwardly of the jaws. Positioning and holding means are provided for locating and holding the strip during the steps of forming the joint between the jaws.