Abstract: A dynamic seat leveling device for a riding lawnmower or tractor has a virtual rotational point located below the leveling device itself. When operated on hilly terrain, such an arrangement accomplishes three objectives: 1) the operator remains level; 2) the operator's center of gravity remains centered directly above a critical balance point which is at ground level, midway between the right and left wheels; and 3) the operator remains at a constant elevation. Keeping the operator at a constant elevation, as the leveling device shifts from one side to the other, minimizes the power that would otherwise be needed to repeatedly raise and lower the operator as the tractor tilts from left to right. Minimizing the power required allows the use of a compact leveling drive that fits between the seat and frame of the tractor.

Abstract: An integral thermoplastic sheet being formed of a plurality of separate sheets welded together in a longitudinal seam along their edges, the seam having been formed by the melting together of the inner surfaces of the separate sheets and being of uniform welded strength in a direction across the seam in a direction transverse to the longitudinal direction of the seam.

Abstract: Apparatus for welding sheets (3a,3b) of thermoplastic material together along proximate edges including a supporting frame (25), a pair of joining rollers (11,13) mounted on the frame and forming a nip (12) with an axis parallel to the axes of the rollers, a motor (23) to drive at least one of the rollers, a horn (15) having a tip (17), and an ultrasonic transducer (39) to reciprocate the horn (15) and tip (17) in the direction of the longitudinal axis of the horn (15), the horn being so positioned in the nip (12) that the tip reciprocates in a direction transverse to the axis of the nip (12), so that proximate edges of the sheets (3a,3b) may move through the nip (12) with one edge on each side of the tip (17), be uniformly melted on their surfaces by frictional energy created by the reciprocal motion of the tip (17), and then be pressed and welded together in the nip (12). Fault detection circuitry stops the operation if the sheet material is not properly overlapping or if it runs out.

Abstract: Apparatus for welding sheets (3a,3b) of themoplastic material together along proximate edges including a supporting frame (25), a pair of joining rollers (11,13) mounted on the frame and forming a nip (12) with an axis parallel to the axes of the rollers, a motor (23) to drive at least one of the rollers, a horn (15) having a tip (17), and an ultrasonic transducer (39) to reciprocate the horn (15) and tip (17) in the direction of the longitudinal axis of the horn (15), the horn being so positioned in the nip (12) that the tip reciprocates in a direction transverse to the axis of the nip (12), so that proximate edges of the sheets (3a,3b) may move through the nip (12) with one edge on each side of the tip (17), be uniformly melted on their surfaces by frictional energy created by the reciprocal motion of the tip (17), and then be pressed and welded together in the nip (12). Fault detection circuitry stops the operation if the sheet material is not properly overlapping or if it runs out.

Abstract: A horn for operation in the sonic or ultrasonic frequency range and made preferably from aluminum or titanium is provided at its lateral surface with a soft metallic coating which acts as a cushion and/or lubricant when the horn accidentally contacts a juxtaposed horn or mechanical fixture. The soft metallic coating in the described embodiment comprises an alloy of tin and lead which is applied over the nickel plated horn surface.

Abstract: A method and apparatus for splicing thermoplastic monofilament material by high frequency vibratory energy use a support having both forming means and an adjoining flash receiving cavity. Monofilaments to be spliced are disposed in the forming means in overlapping relationship. High frequency vibratory energy is applied to the overlap region softening the monofilaments while the excess thermoplastic material created during the splicing is extruded into the adjoining flash receiving cavity. The vibratory energy is removed and the softened material remaining in the forming means solidifies into a continuous monofilament having a predetermined cross sectional area.

Abstract: This invention discloses the plating of a metallic workpiece, particularly aluminum with a layer of tin. The plating is accomplished in the presence of sonic or ultrasonic vibrations at a temperature determined by the phase diagram for a binary alloy to provide for the presence of an alloy interface encompassing both metals. This contrasts with the heretofore achieved adhesive bond.

Abstract: Apparatus for welding sheets (3a, 3b) of themoplastic material together along proximate edges including a supporting frame (25), a pair of joining rollers (11,13) mounted on the frame and forming a nip (12) with an axis parallel to the axes of the rollers, a motor (23) to drive at least one of the rollers, a horn (15) having a tip (17), and an ultrasonic transducer (39) to reciprocate the horn (15) and tip (17) in the direction of the longitudinal axis of the horn (15), the horn being so positioned in the nip (12) that the tip reciprocates in a direction transverse to the axis of the nip (12), so that proximate edges of the sheets (3a,3b) may move through the nip (12) with one edge on each side of the tip (17), be uniformly melted on their surfaces by frictional energy created by the reciprocal motion of the tip (17), and then be pressed and welded together in the nip (12). Fault detection circuitry stops the operation if the sheet material is not properly overlapping or if it runs out.