DE384861C - Electric riveting process - Google Patents

Description

GERMAN EMPIRE

ISSUED NOVEMBER 9, 1923

REICH PATENT OFFICE

PATENT LETTERING

- JVl 384861 - CLASS 21 h GROUP 12

(M 75024 Vllll2ih ^z )

Thomas E. Murray of Brooklyn-New York, V. St. A.

Electric riveting process. Patented in the German Empire on September 4, 1921.

According to the Union Treaty of June 2, 1911, priority is due to this application of the application in the United States of America dated August 26, 1919.

The invention relates to an electric riveting method in which in a known manner electric current through the entire length of one end protruding freely from the workpiece Clever rivets and, by axial pressure, the metal of the protruding part Riveting is compressed.

The method is primarily for joining metal plates to non-metal plates and the like - porcelain, glass, wood, rubber and the like - determined. When riveting Such brittle or flexible materials must be handled with particular care and yet with the usual

When using the riveting method, do not avoid cracking the porcelain or glass or the rivet head is undesirably driven deep into the wood or the like.

The innovation is that rivets are used here, which are on the to be upset Place, i.e. at the protruding end of the rivet, has a smaller cross-section than the rest of the parts of the rivet shank. The end of the rivet becomes ίο soft enough to compress easily while the non-protruding rivet shank part remains hard and retains its shape. The advantages of this process are considerable. The excessive heating of the Plates are avoided, the actual rivet shaft retains its shape, which z. B. at the Making electrical connections is highly desirable, while the foregoing is lead-soft The end of the rivet can be compressed even with moderate pressure. This is particularly beneficial when the upsetting head is on Porcelain or the like can be produced from an uneven surface and with different pressure levels should, because the upsetting head is tightly embedded without the risk of bursting the porcelain firmly a.

Is it about riveting existing porcelain or similar materials? Bodies, the protruding rivet part can therefore close against the porcelain surface in such a way, be squeezed so that it has a head or collar in direct contact forms with the porcelain, and when riveted! metal with porcelain can therefore be used also compress the shaft head on the porcelain.

On the drawing is
Fig. Ι a section of two plates made of metal and glass or porcelain with a hollow rivet; between two electrodes before compression, Fig. 2 the same section with compressed rivet,

Fig. 3 is a view of the glass or porcelain plate with the rivet head produced, Fig. 4 is a section like Fig. 2 in another embodiment of the method.

A is the non-metal plate (glass, porcelain, etc.) to be riveted to the metal plate β. The hollow rivet C inserted through the rivet holes previously created in the plates protrudes by part D above the glass plate Λ , while the rivet head E resting against the metal plate B rests on the stationary electrode F , which is provided with a recess or head shell to accommodate the rivet head can be. The movable counter electrode G has a centering pin H which engages in the hollow rivet shaft.

The plates with the rivet C rest on the fixed electrode F under the movable electrode G, the pin H of which is hollow; Shank of the rivet lies while its end face is in contact with the shank end. If current is sent through the electrodes and the rivets, the protruding shank part D with a smaller cross-section is strongly heated and soft, while the rest of the rivet body, on the other hand, remains relatively cold and hard. If: the electrode G is now driven down, the hollow part D of the rivet shank is pressed together to form an annular head / (Fig. 2), which clings tightly and firmly to the surface of the plate A , so that the two plates A and B are firmly connected to each other between the rivet heads E and I.

! Another advantage of the new process is that there are few differences in the thickness of the plate, as is usually the case with glass and porcelain, does not matter, as the softened metal of the shaft end adapts to every plate thickness and unevenness slightly adapts to the formation of the head. In addition, the cooling of the rivets results in a contraction and therefore contributes to solid associations.

From Fig. 1 it can be seen that and why only a certain part of the rivet shaft is softened. On the one hand, this is due to the weak cross-section through which the; electrical resistance is increased at this point and greater heating is caused, and then on the transfer of heat from the rivet into the metal electrode F and the metal plate B and, to a certain extent, also into the porcelain plate A. But there is also a not inconsiderable amount of heat from the Hollow part D of the rivet shank extends into the upper electrode and its pin H , the lower part of the protruding shank part D will concentrate the most heat, therefore soften the earliest and yield under the pressure of the electrode G , while the shank part located in the plates will change its shape and the end of the shaft on the pin H remains hard enough to maintain its original shape even under the pressure of the electrode if the procedure is properly managed. It has to convert it thus in hand, the entire protruding end of the shaft D into a rivet head as shown in Fig. 2 and 3, or even bring about a kind of compression in the rivet shank just above the plate A. Accordingly, it is also within the scope of the new method to bring about the upsetting at a particularly suitable point of the hollow rivet shank and in any length, to make it usable in all suitable cases, not only for plate connections, but also for joining other types of objects and using them of rivets of any suitable shape.

Heating the rivets to a high degree on a certain or limited portion of their shanks has other advantages. In some cases it is desirable to avoid any excessive heating of one or the other of the parts to be riveted, for example plate B, or one or both ends of the rivet. Is the plate z. B. made of steel with a copper coating, which would be destroyed by excessive heat, the riveting can nevertheless be carried out according to the new method by limiting the harmful temperature level to a central part of the rivet shaft; or if the rivet end is to retain a special shape for electrical contact or the like, this can be achieved using the new method.

The heat is regulated during the actual heating process and is more yielding Pressure is applied by the electrodes until the rivet hardens in place is whereupon its cooling and shrinking take up the resilience of the metal

as and creates a tight bandage. That The method is not only applicable to new rivets, you can also use old, loose rivets Use it to tighten rivets that have become.

When performing the method according to Fig. 4, for example, the end of the hollow shaft of the rivet should retain its shape unchanged. The electrode G is therefore only lowered so far that the middle part of the rivet shank is compressed and shaped into a rivet collar /, while the shaft end Γ retains its shape under this limited compression by being in contact with the electrode G and its pin H gives off heat faster than the middle, therefore softening part /. The protruding part / 'can then later be used, for example, to provide an electrical or mechanical connection with the rivet C, E , also be provided with an internal thread, and given the appropriate dimensioning of the rivet length and the range of movement of the electrode G, can be given any desired length.

In order to reduce the cross-sectional area of the rivet shank for the purpose of softening under the electric heating, only the protruding part D needs to be hollow. In the drawing, the cavity goes deeper, only to save copper. The part of the rivet shank lying in the two plates A and B is kept sufficiently cool and hard by the rapid and abundant heat transfer to the plates.

Claims (4)

Patent Claims: 1. Electric riveting process in which an electric current flows through the whole Length of the rivets protruding freely from the workpiece with one end and the metal of the protruding rivet end is upset by an axially directed pressure, characterized by the use of rivets that have a reduced cross-section at the point of the protruding rivet end to be compressed own. 2. Electrical riveting method according to claim ι for riveting made of porcelain or similar substances existing bodies, characterized in that the protruding The rivet part is compressed against the porcelain surface in such a way that it has a head or compression collar in the immediate vicinity Forms contact with the porcelain. 3. Electrical riveting method according to claim 2, characterized in that at Riveting metal with porcelain the rivet is inserted into the two parts so that his head is resting on the metal and the end of the shaft is upset against the porcelain will. 4. riveting method according to claim 1 to 3, characterized in that the rivet with a hollow shank protrudes from the workpiece and the hollow shank a heat concentration during the passage of the Stromes brings about. 1 sheet of drawings.