DE398688C - Key - Google Patents

Description

Key, which consists of a substantially T-shaped, pre-pressed on the switching part and then double-laid sheet metal strips are already known. With the known keys of this type are the the two side tabs of the sheet metal strip forming the beard flat on top of each other. Consequently On the one hand, the key bit has a low flexural strength, on the other hand ίο the working edges of the key bit must be reached for easy working desired curvature or rounding can be milled, which is especially true for security keys with a stepped beard is cumbersome and time consuming. In addition, it is also impossible to insert the key bit in the usual way to profile, e.g. B. as with slot wrenches, with parallel to the shaft to provide running grooves or grooves. ao For keys with a simple beard, it is already known to round the working edge by having one of the key bits forming sheet metal flap is given a greater length than the other flap and then around the edge of the latter is folded around, or by the fact that the key is from a formed essentially frame-shaped sheet metal plate and thereby the bending point to the The working edge of the key bit is misplaced. But here it is impossible to use the key bit to provide gradations, d. H. to be trained as a security key, rather the key bit can only ever have a single continuous working edge. Further it is due to the fact that the sheet metal tabs forming the beard lie flat on top of one another again also not possible with either of these two known keys, at any point in the Key bit to make a complete groove or groove, as is the case with grooved bit keys is common. The one formed from a T-shaped sheet metal strip A key in which one beard rag reaches around the other is probably a certain one Profiling of the beard possible by the length of the bent sheet metal flap changes. However, this profiling is very limited. It also requires bending one flap around the other two additional bending processes, which makes the production of the key more expensive will.

In the case of the 'subject matter of the invention, consisting of an essentially T-shaped, All these deficiencies are eliminated by the key formed on the shaft part and then pre-pressed and then double-laid sheet metal strips. According to the invention are the edges of the two lateral flaps forming the beard bent against each other, which can be done in a simple manner by pressing in the die. On the one hand, this becomes the key bit very much stiffened, so that bending of the same is impossible. on the other hand It is the case for any desired key beard shape, and not only for keys whose beard is only a continuous one Has working edge, but also with keys with a stepped bit, easily possible, which run parallel to the key shaft Bend up the edges of the sheet metal tabs on the sides so that they form curved working edges on the key bit. That is especially important for keys for Chubb and similar security locks which the key bit simultaneously serves to set several tumblers and to keep them in a certain position during the bolt movement. Furthermore can the now hollow key bit in the manner of the grooved key by arranging a or several grooves are profiled at any point by z. B. in one or the other or both side tabs of the sheet metal strip parallel to the key shaft running grooves are pressed in. Pressing in these grooves can also be done like bending up the edges of the side sheet metal tabs at the same time as pre-pressing of the key shaft, so that for the production of the new key essentially only three work stages, namely the punching out of the sheet metal strip, the pressing of the same in the die and the subsequent folding or bending are required.

By finding it is therefore possible a key made of sheet metal in its shape exactly the same as the one previously cast or forged safety

308088

to replicate keys. The subject of the invention is distinguished from the cast or forged keys but through much easier manufacture and above all by the elimination of the cumbersome and time-consuming milling work. Compared to the known cast keys, the subject of the invention has finally even greater strength. ίο The drawing illustrates two exemplary embodiments of the subject matter of the invention, namely show

Fig. Ι the side view of a key; with a profiled beard,

Fig. 2 is a cross-section through the beard part of the key along the line 2-2 of the Fig.ι and

Fig. 3 to 7 show the various process stages for the production of the key according to Fig. i, Fig. 5 and 6 cross-sections on lines 5-5 and 6-6 of Fig. 4. Fig. 8 shows the side view of a key with a stepped bit and

Fig. 9 is a cross-section through the beard part of the key along the line 9-9 of Fig. 8 again. the

Figs. 10 and 11 show different process stages for producing the key according to Fig. 8.

To produce the key shown in Fig. 1, a sheet metal strip of the essentially T-shaped outline figure shown in Fig. 3 is used as a preliminary workpiece. The middle divider of this sheet metal strip, which should form the shaft of the key! is, as is known per se, pressed in such a way that it has the trough-shaped cross-section best shown in FIG. At the same time, the edges of the two lateral flaps b, b , which produce the key bit, are pressed up, the edges b ¹ lying parallel to the key shaft being given a curved shape, while the remaining edges can be bent up at sharp angles. The pre-pressed workpiece according to Fig. 4 to 6 is now bent together around the center line AA so that the two halves of the sheet metal strip come to rest with their upturned edges (see Fig. 2). On the one hand, the two tabs of the pre-workpiece forming the key bit are firmly connected to one another by a rivet c , while at the rear end of the hollow shaft part a, as is known, the grip partii consisting of a special sheet metal strip is inserted and also fastened by means of a rivet / the purpose for which the pre-workpiece (Fig. 3) must of course be provided with rivet holes in the appropriate places.

As can be seen, those abutting edges b ¹ , b ^{1 of} the side tabs b, b, which run parallel to the key shaft, form a curved working edge on the key bit, which ensures that the key works properly in the lock without reworking by milling or the like is. Because the key bit is hollow as a result of the bent-up edges of the tabs of the sheet metal strip that form it, it can be profiled as desired. In the example it is provided with a groove g running parallel to the shaft, which is formed by ^{a groove g 1 being} pressed into one of the two lateral tabs b of the preliminary workpiece (see Figs. 4 and 6).

The key shown in Fig. 8 is also made from a sheet metal strip of essentially T-shaped outline (Fig. Ro). Only the two lateral tabs b, b of the sheet metal strip of the desired gradation of the key bit are cut out accordingly. The middle, the "key shank resulting part" of the pre-workpiece is again pressed into a trough shape, while the edges of the side parts b, b are pressed up, with, as previously described with reference to the embodiment of Figs. 1 to 7, those edges b ¹ , which the working edges of the beard steps result, are slightly arched so that they result in arched working edges on the key bit when the sheet metal strip is bent together. The two side tabs of the workpiece lying on top of one another with their upturned edges are also connected to one another again by a rivet and thereby firmly pressed together, while the handle d is fastened in the rear end of the shaft part α. The manner of fastening ¹ Qo of the handle part is irrelevant to the invention, optionally, the handle could also be connected to the shaft and the beard in one piece, by the whole key from a single, correspondingly cut-out sheet-metal strip is formed.

Claims (1)

Patent claim: A key formed from an essentially T-shaped, pre-pressed and then doubled sheet metal strip on the shaft part, characterized in that the edges of the two lateral tabs (b, b) of the sheet metal strip forming the key bit are bent towards each other so that the key bit is hollow. 1 sheet of drawings.