CPC Definition - Subclass B21J
This place covers:
General metal forging or pressing methods, devices and furnaces. Riveting is traditionally part of forging.
Forging is a manufacturing process involving the shaping in the thickness of a solid metal billet using localized compressive forces at a temperature below fusion.
This subclass subdivides into:
Methods | |
Machines | |
Furnaces; Blacksmiths requisites | |
Riveting |
Example: a forging process for manufacturing a coupling member with splines by closed-die forging, would be classified in B21K 1/762 (making a forged coupling member), in B21J 5/12 (forging profiles) and B21J 5/02 (die forging).
- B21J comprises forging machines (B21J 7/00 - B21J 13/06) and accessories for forging machines (B21J 13/08 - B21J 19/04). Further accessories are to be found in B21K (handling devices in B21K 27/00, arrangements for cooling and heating B21K 29/00, control devices specially adapted for positioning tool carriers B21K 31/00).
This place does not cover:
Methods of forging specific products | |
Finishing surfaces by hammering |
Attention is drawn to the following places, which may be of interest for search:
Rolling of metal | |
Bending or deep-drawing | |
Uniting components by forging | |
Handling devices for forging | |
Heating or cooling devices for forging | |
Control devices for forging | |
Casting | |
Powder metallurgy | |
Cladding or plating | |
Compacting surfaces by blasting with particulate material | |
Working of plastic material | |
Presses in general | |
Embossing for making artistic work | |
Furnaces in general |
This place covers:
Forging processes for producing elementary billet shapes, either as rough forging or as preliminary forging; heating and cooling processes
Attention is drawn to the following places, which may be of interest for search:
Pretreatment by rolling |
This place covers:
Processes for preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, descaling by forging, changing the material structure.
This place covers:
Processes for shaping in the rough, i.e. making basic shapes (square, round), especially for billets leaving the continuous casting line.
This place does not cover:
Preliminary treatment of metal stock without particular shaping | |
Combination of metal rolling and forging |
This place covers:
Processes for heating or cooling before or during forging
This place does not cover:
Friction heat forging | |
Forging furnaces | |
Arrangements for heating or cooling during forging |
Attention is drawn to the following places, which may be of interest for search:
Cooling or heating metal sheets for or during bending or deep drawing |
This place covers:
Processes for lubrication forging material or dies.
.
This place does not cover:
Arrangements for lubricating during forging |
Attention is drawn to the following places, which may be of interest for search:
Lubricating during pressing metal sheets | |
Lubricating other machines | |
Lubricating presses in general | |
Lubricants | |
Lubricating in general |
This place covers:
Method for forging using open dies.
This place does not cover:
Attention is drawn to the following places, which may be of interest for search:
Working metal sheet, tubes, rods, or profiles |
This place covers:
- Method for forging using closed dies.
- Trimming using dies.
Attention is drawn to the following places, which may be of interest for search:
Extrusion of metal |
This place covers:
Methods for forging, hammering or pressing by directly applied fluid pressure or explosive action
This place covers:
Methods for forging, hammering or pressing by performing particular operations
This place covers:
Methods for forming a workpiece by pressing, a portion of the workpiece being locally heated by friction against the working tool
Attention is drawn to the following places, which may be of interest for search:
Friction heat riveting | |
Uniting components by friction heat forging | |
Friction stir welding |
This place covers:
Methods for forming a hole into a workpiece by pressing a forming tool rotating at high speed, the pressed area being locally heated by friction
Attention is drawn to the following places, which may be of interest for search:
Forming branched tubes by flow drilling |
This place covers:
All aspects relating to shaving, skiving or scarifying for forming lifted portions, e.g. slices or barbs, on the surface of the material.
Attention is drawn to the following places, which may be of interest for search:
Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies | |
Other methods for working sheet metal, metal tubes, metal profiles | |
Making heat exchangers, e.g. radiators, condensers, of metal tubes | |
Making heat exchangers | |
Attachment of friction linings | |
Tubular elements or assemblies thereof with means for increasing heat-transfer area being integral with the element | |
Plate-like elements or assemblies thereof with means for increasing heat-transfer area with recesses, grooves, or microchannels | |
Details of semiconductor with cooling facilitated by foil-like cooling fins or heat sinks | |
Modifications to facilitate cooling, ventilating, or heating of electrical apparatuses |
This place covers:
Methods for piercing a billet using a forging or pressing tool
This place does not cover:
Piercing presses | |
Piercing in combination with extrusion |
This place covers:
Methods for making profiles, e.g. grooves, splines, on internal or external surfaces of a workpiece
Attention is drawn to the following places, which may be of interest for search:
Methods for forging gears | |
Methods for forging screw-threads | |
Methods for forging profiles on thin or sheet like metal billets |
This place covers:
Forging hammers. Hammers act by impact against the workpiece, each hammer stroke lasting about some milliseconds.
This place does not cover:
Forging presses | |
Deforming metal sheet by hammering | |
Hand hammers |
This place covers:
Forging hammers of particular design or construction
This place covers:
Drop hammers with rigidly guided hammer.
This place covers:
Hammers characterised by the fact that drive and hammer a connected via a fulcrumed lever, e.g. tail hammer
This place covers:
Hammers characterised by the fact that drive and hammer a connected via a fulcrumed lever, said fulcrumed lever being a spring, e.g. spring hammers.
This place covers:
Hammers of the type having more than one moving hammer.
Attention is drawn to the following places, which may be of interest for search:
Hammers with both hammer and anvil moving |
This place covers:
Hammers of the type having several radially striking hammers, actuated by the rotation of an annular member. Although this is not excluded, the hammers are usually not rotating.
Attention is drawn to the following places, which may be of interest for search:
Hammers in rotary arrangements |
This place covers:
Hammers of the type having several radially striking hammers, actuated by their rotation inside an annular member. Although this is not excluded, the annular member is usually not rotating.
Attention is drawn to the following places, which may be of interest for search:
Hammers actuated by a rotating member |
This place covers:
Hammers of the type carrying die jaws, e.g. pivoted, movable laterally of the forging or pressing direction.
This place covers:
Power hammer drives of the type operated by steam, air or other gaseous pressure.
This place covers:
Power hammer drives of the type operated by internal combustion, e.g. a diesel engine.
This place covers:
Power hammer drives of the type operated by hydraulic or liquid pressure, e.g. water
This place covers:
Power hammer of the type the hammer and the anvil are operated
Attention is drawn to the following places, which may be of interest for search:
Machines working with several hammers |
This place covers:
Drives for drop hammers, i.e. of the type lifting the hammer after the forging stroke (falling movement of the hammer is only due to gravity)
This place covers:
Drop hammers operated by rotary drive, the hammer being linked to the drive via a belt rope, cable, chain or board.
This place covers:
Control devices specially adapted to forging hammers
This place does not cover:
Control devices for tool carriers |
Attention is drawn to the following places, which may be of interest for search:
Cyclically operated valves | |
Automatic controllers |
This place covers:
Forging presses of particular design or construction
This place covers:
Forging press carrying several dies, each die corresponding to a workpiece manufacturing step.
Attention is drawn to the following places, which may be of interest for search:
Bolt, rivet, nut forging processes | |
Handling devices |
This place covers:
Forging presses carrying rolling or wobbling dies
Attention is drawn to the following places, which may be of interest for search:
Riveting machine of the wobbling type |
This place covers:
Forging presses specially adapted for swaging.
Forging presses specially adapted for upsetting.
Attention is drawn to the following places, which may be of interest for search:
Methods of upsetting |
This place covers:
Forging presses specially adapted for upsetting and equipped with devices for heating the workpiece.
Attention is drawn to the following places, which may be of interest for search:
Electric heating elements |
This place covers:
Drives for forging presses operated by hydraulic or liquid pressure
This place covers:
Drives for forging presses operated by hydraulic or liquid pressure in conjunction with steam or gas power. Are also classified there drives for forging presses operated by steam or gas power.
This place covers:
Drives for forging presses operated by gearing mechanisms (levers, spindles, crankshafts, eccentrics, toggle-lever, rack bars...)
This place covers:
Control devices specially adapted for forging presses.
Attention is drawn to the following places, which may be of interest for search:
Control devices for tool carriers | |
Cyclically operated valves | |
Automatic controllers |
This place covers:
Machines combining aspects of forging hammers and forging presses
This place covers:
Details of forging hammers or presses, e.g. dies, die mountings, frames, guides, hammer tups, anvils, accessories for handling work or tools.
This place covers:
Particular aspects of dies, e.g. die constructions, specific features.
This place covers:
Details of die mountings
Attention is drawn to the following places, which may be of interest for search:
Handling of tools |
This place covers:
Details of frames of guides in forging machines.
This place covers:
Details of hammer tups, anvils, anvil blocks.
This place covers:
Details of the accessories for handling heavy workpieces, e.g. benches.
Attention is drawn to the following places, which may be of interest for search:
Handling light workpieces in multi-stage presses | |
Handling light workpieces |
This place covers:
Details of the accessories for handling tools.
This place does not cover:
Die mountings |
This place covers:
Details of devices for manipulating heavy workpieces.
Attention is drawn to the following places, which may be of interest for search:
Handling light workpieces in multi-stage presses | |
Handling light workpieces | |
Manipulators in general |
This place covers:
Devices adapted to turn heavy workpieces during forging.
This place covers:
Devices for ejecting the workpieces from the forming die.
This place covers:
All aspects of riveting. This group can be considered independent from the remaining of B21J. It is structured as follows:
Riveting methods | |
Riveting machines | |
Riveting accessories | |
Removing rivets |
A rivet is an element(1) specially(4) designed to connect two or more(2) workpieces under plastic deformation(3) of said element. See explanations of (1)-(4) in the glossary.
This place does not cover:
Chirurgical riveting | |
Plastic riveting |
Attention is drawn to the following places, which may be of interest for search:
Buttons | |
Sealing | |
Clinching workpieces | |
Feeding elements | |
Setting pierce-nuts | |
Setting screw-threaded nuts | |
Riveted connections | |
Adhesive | |
Rivets | |
Electrical elements |
In this place, the following terms or expressions are used with the meaning indicated:
Element | Workpieces connected without use of an additional element are not riveted (e.g. a first metal sheet pressed into the hole of a second metal sheet is clinched, but not riveted, see picture). |
Connect two or more | Elements that do not connect two or more workpieces, but still are designed to be inserted into a single workpiece by deformation of said element are normally not considered as rivets (e.g. connecting nuts, see picture). |
Plastic deformation of said element | An element that does not undergo plastic deformation is not a rivet (e.g. a screw, a nail do not deform). |
Specially | Elements that usually have a different use (e.g. a tube, a gear) but still are used to connect two or more workpieces by the deformation of said element are usually not considered being rivets (such connections are usually in B21K 25/00 , see picture). |
This place covers:
Riveting procedures. The procedure mainly depend on the type of rivet. So each group from B21J 15/02 - B21J 15/08 mainly correspond to a different type of rivet.
B21J 15/02 relates to setting the "standard" rivets, i.e. solid cylindrical piece of metal having or not a head at one end thereof. These rivets are riveted by applying axial pressure to form the end(s) having no head into a head.
Attention is drawn to the following places, which may be of interest for search:
Solid rivets per se |
This place covers:
Setting rivets of the "lock bolt" or "swaged on locking collar" type: the rivet is made of a stem / mandrel having grooves on the periphery, and having a head at one end. A ring is pressed from the opposite side, along the cylinder body into the grooves (see figure 1a before setting, figure 1b after setting).
Attention is drawn to the following places, which may be of interest for search:
Bolts fastened by swaged-on collars per se |
This place covers:
Setting rivets of the "self-piercing" type: the workpieces to be joined have no hole drilled in advance. The rivet is punched by axial pressure into the workpieces, either partially or completely.
Attention is drawn to the following places, which may be of interest for search:
Clinching | |
Setting pierce nuts | |
Self-piecing rivets per se |
This place covers:
Setting rivets of the "friction heating" type: deformation of the rivet is obtained by pressing and turning a tool (or the rivet) to such a speed, that part of the rivet is heated above melting point.
Attention is drawn to the following places, which may be of interest for search:
Friction heat forging | |
Making connections by friction heat forging | |
Friction stir welding |
This place covers:
Setting hollow rivets, e.g. of the type where a first hollow semi rivet is inserted from a first side of the workpieces into a second hollow semi rivet inserted into the workpieces from the opposite side.
Attention is drawn to the following places, which may be of interest for search:
Hollow rivets, multi-parts rivets per se |
This place covers:
Setting hollow rivets of the type where a mandrel is pushed into a rivet in order to expand said rivet.
Attention is drawn to the following places, which may be of interest for search:
Blind rivets fastened by a drive-pin |
This place covers:
Setting rivets by pulling a (usually breakable) mandrel, which deforms the head of the rivet (and usually breaks, see e.g. pop rivets). If the mandrel belongs to the machine, and can be screwed / unscrewed inside the rivet head, then these rivets belong to B25B 27/00: screw-threaded nuts.
Attention is drawn to the following places, which may be of interest for search:
Hand tools for setting screw threaded nuts | |
Hollow rivets fastened by a pull-mandrel per se |
This place covers:
Setting rivets using swaged locking means, usually an additional ring, or an additional part of the mandrel is expanded into the rivet body (see ring 11 in the attached figure).
This place covers:
Setting rivets by "edge curling": the rivet is hollow, like a small tube, and the ends of the rivets are rolled backwards. An alternative is a hollow rivet having an end closed, said end being expanded by means of a hook.
This place covers:
Setting of "self-drilling" rivets: the rivet is provided with a small drilling head, and is rotated to drill the hole it should be inserted into.
Attention is drawn to the following places, which may be of interest for search:
Self-drilling rivets per se |
This place covers:
Setting rivets, wherein a fluid pressure, e.g. hydraulic, liquid or gas, is fed directly inside the rivet in order to deform it.
This place covers:
Applying additional heat to the rivet or to the workpiece.
Attention is drawn to the following places, which may be of interest for search:
Setting rivets by friction heating | |
Electrical heating |
This place covers:
All aspects relating to riveting machines.
Attention is drawn to the following places, which may be of interest for search:
Machines for setting pierce nuts | |
Machines in general |
This place covers:
Riveting hand tools operated by hydraulic, liquid, gas, or electricity, i.e. any force which is not the force of the hand.
This place does not cover:
Pliers, i.e. riveting tools actuated by the force of the hand |
Attention is drawn to the following places, which may be of interest for search:
Screw threaded nuts setting machines |
This place covers:
Machines having an additional movement to the feed movement, e.g., vibration, rotation (wobble die).
This place does not cover:
Setting rivets by friction heating | |
Setting self-drilling rivets |
Attention is drawn to the following places, which may be of interest for search:
Forging presses with wobbling dies |
This place covers:
Machines for manufacturing brake lining machines, turbines, riveting into composite, and everything relating to aerospace construction (usually machines having specific frames for airplanes or associated with a drilling tool). The picture represents typical brake lining.
This place covers:
Machines for manufacturing aerospace structures, mainly either machines having a working head with multiple tools (e.g. driller, riveter, sealer) or machines designed to work on large structures (e.g. riveting an airplane ring or airplane section).
Source: EP1884313; US2011119897
This place covers:
Machines for manufacturing turbines.
Source: JP61189837
This place covers:
Machines for riveting composite articles.
Source: DE102009037245
Attention is drawn to the following places, which may be of interest for search:
General aspects of joining of plastics |
This place covers:
Motors being used as drives for riveting and transmissions therefore, e.g. in machines working with chains or belts.
This place covers:
Air or gas motors for riveting machines.
Attention is drawn to the following places, which may be of interest for search:
Drives operated by gas and hydraulic or liquid pressure |
This place covers:
Drives for riveting using hydraulic or liquid pressure.
This place covers:
Drives for riveting where the pressure comes from a hand operated pump.
This place covers:
Drives for riveting combining air (or gas) and hydraulic (or liquid) pressure, usually by means of an intensifier. This combination is common in riveting hand tools, where a piston actuated by a primary pressurised air circuit (coming from pipes in the factory) is used to build pressure into a hydraulic circuit of the riveting tool, which serves to deform the rivet. The following figure discloses such an intensifier 22, 25, 26.
Attention is drawn to the following places, which may be of interest for search:
Drives operated by gas and hydraulic or liquid pressure | |
Drives operated by hydraulic or liquid pressure |
This place covers:
Drives for riveting using electromagnets (e.g. a capacitor is suddenly discharged into an electromagnet to create a sudden repulsion force of a permanent magnet). Electric actuators not belonging to B21J 15/26.
This place does not cover:
Drives for riveting using an electric motor |
This place covers:
Drives for riveters using an electric motor.
This place covers:
Control devices, which are understood to be any device influencing the sequence of operation of the machine in addition to basic machine movement command. As example, control includes checking positioning of the rivet or the workipece, checking the operator's security.
This place covers:
Controls the rivet deformation parameters during setting, e.g. force vs. time, strain vs. time...
This place covers:
Devices for feeding rivets, anywhere from the storage bowl to the riveting head.
Attention is drawn to the following places, which may be of interest for search:
Feeding welding pins | |
Feeding articles for assembling machines | |
Magazines for machine tools | |
Feeding screws | |
Articles attached to webs | |
Conveying articles through pipes | |
Nails or staples formed in integral series | |
Devices for fastening nails, bolds or nuts |
This place covers:
Devices for feeding rivets, attached to a carrier strip.
Source: EP0928650
This place covers:
Devices for collecting broken-off mandrels or stems.
Source: WO2004048011
This place covers:
Feeding tubular rivets of the multiple rivet type.
Source: GB642664
This place covers:
Details of die forming heads or rivet forming parts.
This place covers:
Details of mandrels for forming hollow rivets.
Attention is drawn to the following places, which may be of interest for search:
Setting rivets by means of a mandrel | |
Hollow rivets fastened by a pull mandrel |
This place covers:
Accessories in connection to riveting. Hand actuated tools and rivet removing equipments are considered accessories.
This place covers:
Hand tools used for or in connection with riveting, which are actuated without energy supply: the force comes from the hand.
Source: EP0447901
This place does not cover:
Portable riveters | |
Pliers for riveting |
This place covers:
Pliers for riveting, i.e. actuated without energy supply: the force comes from the hand.
This place does not cover:
Portable riveters |
This place covers:
Accessories for forming rivet heads.
This place covers:
Special clamping devices: specific tools to press the workpieces one against the other before riveting.
This place does not cover:
Pressing device integrated into the riveting tool |
This place covers:
Riveting holes positionners to position the tool with regard to the hole.
This place covers:
Positionners for rivets when making tube joints.
This place covers:
Devices for caulking rivets, i.e. re-working the rivet head after setting, to change the shape, or push the button sides into the workpieces.
This place covers:
Removing rivets which are installed and need to be removed, e.g. by cutting, shaving or drilling
This place does not cover:
Jigs for drilling rivets | |
Removing sleeves | |
Hand cutting tools | B26D17/00 |
This place covers:
Details of the furnaces specifically adapted for forging
Attention is drawn to the following places, which may be of interest for search:
Heating or cooling methods | |
Furnaces for heat treatment of ferrous or non-ferrous metals or alloys | |
Furnaces for heat treatment |
This place covers:
Details of the electrically heated furnaces specifically adapted for forging
Attention is drawn to the following places, which may be of interest for search:
Electric heating elements |
This place covers:
Blacksmiths requisites, i.e. requisites for hand forging
This place covers:
Hearths; Air supply arrangements specially adapted therefor
This place covers:
Tyre heaters, e.g. for heating train wheels.