Abstract: Variable amplitude, linear reciprocation of an output ram is produced by converting rotary motion into linear motion using a swash plate connected by a bending element to drive a crank. The rotary prime mover and swash plate are mounted on a pivotable frame so as the axial throw of the swash plate is determined by the angular offset of the rotational axes of the swash plate and crank. When the axes are coincident the throw, and therefore the ram stroke, is zero but progressive angular displacement produces a progressively increased stroke. Thus, the frequency of reciprocation is determined by the angular speed of the prime mover, and the stroke is controllably variable between maximum and zero.

Abstract: The frictional loads involved in a friction welding operation, for joining metal parts, may be several tons and the mass of the welding apparatus is correspondingly large. Thus, in addition to the energy which is converted into heat at the weld interface a substantial amount of work has to be done simply to overcome the inertial loads of the apparatus. An inertial load cancelling system is proposed in which a double acting gas spring arrangement is coupled to the welding oscillator output so that the work done in overcoming the inertia of the apparatus is returned to the system when the oscillator motion is reversed at the ends of each stroke. Thus, after the initial system input the oscillator has only to supply work to overcome internal frictional and that converted to frictional heat at the weld joint interface.

Abstract: In a friction bonding operation the friction generating and weld forming forces are usually applied perpendicular to the joint faces. Thus, whenever the joint angle changes to component cassette part of the welding machine must be reset to a new angular orientation. This situation arises in the manufacture of a compressor BLUM (Bladed drUM) for a gas turbine engine, where the blades in successive stages are set at different HADE angles. The invention provides an improved component cassette in which the HADE angle is ignored. The cassette is interlocked with the workplace holder to provide a closed force loop to contain out-of-plane forces while retaining sufficient degrees of freedom to allow the friction generating and welding movements to proceed unimpeded.

Abstract: A new method of friction welding, particularly suitable for manufacturing BLISKS and BLUMS for gas turbine engine rotors, in which the disc or drum rotor is angularly reciprocated while the airfoil blades are pressed radially against the rotor circumference. A machine for carrying out the method has a workpiece holder and a counterbalancing member mounted for angular reciprocation and coupled together by torque transfer means to constitute a resonant system. In operation the machine is driven at or near its natural frequency of oscillation. The natural frequency can be tuned by adjusting the stiffness of the torque transfer means. The machine also includes a drive mechanism.

Abstract: Holding means for a component in a friction welding operation consists of a hollow cassette which is open at one end. The component is inserted into the cassette through an aperture at the open end that is shaped to frictionally engage a thickened portion of the component with a force greater than forces transmitted to the component during a friction welding operation. The component is pressed into the cassette to a predetermined depth so that a portion of it protrudes and forms the weld interface. Material upset during the welding operation may be sheared by increasing the weld generating force to overcome the frictional holding force so the end face passes over the weld region.

Abstract: A component holder for a friction welding apparatus has upper and lower clamp members which can be urged towards each other in order to clamp between them a component to which second or further components are to be friction welded. The first component is held in the component holder substantially entirely by friction clamping forces. The component holder is particularly suited to use with friction welding apparatus in which the component holder is carried by an angularly reciprocable workpiece mounting member.

Abstract: A workpiece holder for angularly reciprocatory friction welding apparatus includes clamp members for clamping the workpiece to a mounting table. The height and circumferential position of a drum is adjustable to facilitate blade attachment in manufacture of a blum. Means are also described for reinforcing the drum during blade attachment in order to absorb welding forces which might otherwise distort the drum surface.

Abstract: A control system for controlling the temperature within process machinery such as the feed assembly in an injection molding machine. The control system provides a six phase process for starting up the machine from cold conditions and controlling the machine temperature to rapidly and accurately attain a command temperature while identifying control parameters for use under steady state conditions for maintaining the command temperature.

Abstract: The present invention consists in the apparatus for use in welding a first component and a second component together by friction welding, comprising drive means operative to generate reciprocatory movement, a component holder operative to hold said first component, linking means operative to transmit reciprocatory movement from the drive means to the component holder so that in operation said first component performs reciprocatory heat-generating movement, pressure means operative to exert pressure on the component holder so that in operation said first component also performs welding movement, the linking means being such as to accommodate that welding movement during friction welding and the pressure means being such as to accommodate that heat-generating movement during friction welding.

Abstract: A friction welding reciprocator comprises first chamber means defining a first chamber containing a substantially fixed volume of hydraulic fluid, second chamber means defining a second chamber containing a substantially fixed volume of hydraulic fluids, reciprocable driving means comprising a plurality of individual reciprocable elements, reciprocable driven means, a reciprocating mechanism operatively connected to said reciprocable elements, and adjustment means; wherein reciprocation of said reciprocable elements by said reciprocating mechanism causes a local variation in the shape and volume of said first chamber and complementary local variation in the shape and volume of said second chamber, and wherein said reciprocating mechanism is couplable to said reciprocable elements so as to cause reciprocation of said elements at the same frequency with unvarying amplitudes, and said adjustable means is adjustable to vary the relative phases of reciprocation of said reciprocable elements to a condition where th

Abstract: In a known method of friction welding two workpieces together, one workpiece is reciprocated relative to the other while the workpieces are pressed together. When sufficient frictional heat has been generated, relative movement is caused to cease and the workpieces become welded. Apparatus for carrying out that method comprises power-driven reciprocatory means which carries the reciprocating workpiece. To balance the reciprocatory means there are counterweights which move in the opposite direction to the reciprocatory means. Each counterweight is constrained by guide means to move along a rectilinear path. Each counterweight is coupled to the reciprocatory means by reversing means, which comprises a pivoted rocker, first linking means and second linking means. Each linking means may be constituted by a flexible blade which is anchored in a non-pivotal manner to the reciprocatory means, the rocker or the counterweight, as the case may be.

Abstract: In one method of friction welding two workpieces together, one workpiece is reciprocated while the other is pressed against it. When sufficient frictional heat has been generated, relative movement is caused to cease and the workpieces became welded. The invention provides apparatus comprising mechanism for effecting reciprocation of a ram (11) and for reducing its stroke rapidly to zero. The mechanism comprises rotatable eccentrics (3, 3') with followers (4, 4') connected by flexible blades (7, 7') to reciprocable elements (5, 5'). Those elements are in turn coupled by flexible blades (10, 10') to opposite ends (8, 8') of a rockable linking body ( 9, 101). A central part of the body is connected by a flexible blade (12) to the ram. The eccentrics rotate at the same speed. When in phase they reciprocate the linking body and ram, but when out of phase the linking body rocks and the ram remains stationary. Adjustment means (41) enables the phase of the eccentrics to be rapidly altered while they rotate.