National Research Development Corporation

Sprayforming Developments Limited of Innovation Center

Dennis H Sansome

Gerald M Jones

Alfred R Singer

Thiam Beng Lim

Basily B Basily

Graham R Dawson

Ibrahim N Ibrahim

Vibrating ring motor for feeding particulate substances

On spray-forming metals onto a substrate from which the sprayed coating is to be detached, unwanted adhesion may occur, even to a smooth substrate. Conversely, if the coating is meant to adhere, it may accidentially delaminate, even from a roughened substrate. By vibrating the substrate, marginally adherent splats will be encouraged to detach themselves while, on the other hand, well adherent splats will not be affected.

Spray depositing of metals

A ring-shaped device for interposing between two bodies, to measure the force tending to urge them together or pull them apart in a direction coaxial with the ring. Both axial ends of the ring are robust and resist distortion, but between its ends the ring is of convoluted section so that when the ring shortens or lengthens axially under the applied load, hoop stresses are set up in the convoluted part. These stresses are detected by strain gauges located at intervals around the circumference of that part of the ring. The ring may be contained within a protective cylindrical casing, so designed as not to prevent the full magnitude of the applied load being communicated to the ring inside. To improve linearity of the correlation between the applied load and the response of the strain gauges, a stiffening ring may be attached coaxially to the ring; this sleeve may have robust axial ends, and a thinner cylindrical center part registering with the convoluted part of the ring.

Load measuring devices

A variable-geometry plug for use in the plug drawing of tube or other elongated hollow stock. The plug comprises first and second coaxial and relatively-movable parts which co-operate with a deformable annular sealing ring. With the two parts so disposed that the ring is relaxed, the plug can be inserted easily into the undrawn stock. In use, the two parts are caused to move relative to each other, so deforming the ring that it seals an annular clearance between the plug and the undrawn stock. If lubricant is then provided at the upstream face of the seal, the movement of the stock over the seal then tends to draw that lubricant forward across the seal by hydrodynamic action, so tending to fill the clearance with that lubricant at an enhanced pressure. Plugs are described in which this hydrodynamic pressurization is augmented by fluid under pressure supplied direct to the clearance through conduits including passages formed through the body of the plug. Plugs connected to solid bars and flexible leads, and also truly 'floating' plugs no such connection, are described.

Plug drawing of tubes and other hollow items

A plug assembly for use in the plug drawing of tubes and like hollow workpieces. In axial succession, from front to rear, the plug comprises three parts in fixed relationship to each other: a foremost first part with a smoothly rounded nose to make smooth and positive contact with the tube at the start of drawing, a parallel-sided middle part which sizes the interior section of the product as drawing proceeds, and a long rearmost part of larger section. During drawing the confronting surfaces of the rear part and the bore of the undrawn tube define a thin cylindrical clearance, relative movement between the walls of which exercises a hydrodynamic action upon lubricant lying within the tube rearward of the plug, forcing that lubricant forward through the clearance into the region where tube and plug first make contact. Alternative plug shapes for the third part of the plug are proposed, including parallel-sided, stepped and sloping.

Plug drawing

A variable-geometry plug for use in the plug drawing of tube or other elongated hollow stock. The plug comprises first and second coaxial and relatively-movable parts which co-operate with a deformable annular sealing ring. With the two parts so disposed that the ring is relaxed, the plug can be inserted easily into the undrawn stock. In use, the two parts are caused to move relative to each other, so deforming the ring that is seals an annular clearance between the plug and the undrawn stock. If lubricant is then provided at the upstream face of the seal, the movement of the stock over the seal then tends to draw that lubricant forward across the seal by hydrodynamic action, so tending to fill the clearance with that lubricant at an enhanced pressure. Plugs are described in which this hydrodynamic pressurization is augmented by fluid under pressure supplied direct to the clearance through conduits including passages formed through the body of the plug. Plugs connected to solid bars and flexible leads, and also truly 'floating' plugs no such connection, are described.

Apparatus for draw-bending metal tubes and other elongated workpieces of hollow section, in which a mandrel, supported on a bar within the tube, bears against the inner wall of the tube in the region of the bend and helps to prevent the tube section from collapsing or distorting. Vibration transducers are attached to the bar to set up a standing wave of resonant vibration within the mandrel and bar which has the effect of reducing friction between the mandrel and the tube. A special coupling device may be used to attach the transducers to the bar and may also serve to connect the bar to the fixed structure of the apparatus, and the invention includes the complete apparatus when tuned so as to generate a displacement antinode of vibration at the mandrel tip, a displacement node at the point of attachment of the coupling device to the structure, and generally so as to minimize waste of the vibratory energy.

Draw-bending method

A plug for use in the plug drawing of hollow tubes or other stock. A flexible and deformable seal is mounted on the rearward part of the plug. In its relaxed state this seal allows easy insertion of the plug into the stock before drawing begins. In its deformed state, which it is caused to adopt in use, it effectively seals the rearward end of a cylindrical clearance between the plug and the stock, so enabling this clearance to be filled with pressurized lubricant to improve drawing efficiency. The lubricant is supplied through passages formed in the plug and connected to a hollow conduit extending backwards within the undrawn stock. The conduit may be flexible, or may be rigid and then act as a plug bar. The plug may be in two parts which are caused, as drawing begins, to move relative to each other and in so doing to deform the seal.

A load-measuring device, comprising a ring to be interposed between two opposed bodies coaxial with the load axis. Circumferentially-spaced projections separate one axial face of the ring from one of the bodies, and similar but angularly-staggered projections separate the other axial face from the other body, so that when the bodies approach under load the ring is distorted to an undulating shape. The distortion may be measured by a set of strain gauges fixed to the axial faces of the ring, and the output of a second set of gauges fixed to the radial faces of the ring may serve to compensate for distortions of the ring caused by things other than axial thrust, e.g. temperature variation. The projections may be fixed to the ring, or fixed to and located by the ring casing so that they bear against the ring in use.

Load-measuring devices

Method and apparatus for deforming the section of material by forcing it, e.g. punching or drawing it, through a die. The die, die holder and workpiece are vibrated in tune, e.g. acoustically, so that points on the walls of the die orifice oscillate in a direction lying generally radial to the die axis. This causes the die to exert a swaging action upon the material and contribute to the deformation thus reducing the power needs for forcing the workpiece through the die and increasing the maximum deformation obtainable.

Growing community of inventors

Sutton Coldfield, United Kingdom

Dennis H Sansome