The present invention relates to a method and apparatus for forming a profile groove in an elongated key blank having opposite side surfaces.
The normal way of forming profiles grooves in the sides of a key blank made of a durable material, such as brass, or so called “nickel silver”, or some other metal alloy, is to use a rotating cutter disc which operates in a side surface of the key blank so that the material is cut away and a groove is formed, while moving the axis of the cutter disc linearly along the key blank.
However, the shape of the profile groove formed by such a conventional method is limited. Of course, the disc can be oriented at an angle relative to the key blank surface, and it is also possible to modify the shape of the peripheral, active surface of the cutter disc to some extent. Even so, there are numerous geometrical shapes of profile grooves that need other or additional forming methods, in particular undercut profile grooves of various geometrical shapes.
It is known per se to use linearly guided punching tools with one or more teeth, such as broaches with several teeth, for making profile grooves in key blanks. See e.g. the published international patent application WO/2010/095997 (WINLOC AG), page 2, last paragraph. Such tools are guided and forced linearly in parallel to the key blank while forming a profile groove, such as an undercut groove.
However, there are limitations as to the possible geometrical shapes that can be made with such punching tools. The forces are very strong, and there is a clear risk that the material of the key blade will start to float adjacent to the groove being formed in this way, especially if the wall between the inside of the groove and the outer surface of the key blank is relatively thin. Thus, there is a great risk that the key blade will be deformed during this forming process, making the finished key useless.
Against this background, it is an object of the invention to provide a method and an apparatus that makes it possible to use linearly guided punching tools or broaching tools when making profile grooves in key blanks, without deforming the material of the key blank adjacent to the profile groove being formed in a surface of the key blank.
It is also an object to provide a method and an apparatus for groove making that is suitable for serial production of keys in large numbers, at relatively high speed.
Furthermore, the method and apparatus should be reasonable in cost and easy to operate.
A method according to the invention, which overcomes the problems indicated above, involves the steps of
forming a profile groove in a side or edge surface of a key blank by means of a punching or broaching tool with at least one cutting tooth which is forced and guided longitudinally in parallel to said elongated key blade so as to cut out the material of said key blank into the desired shape of the profile groove, corresponding to the cross-sectional shape of said at least one cutting tooth, while
at the same time holding said opposite side surfaces of the key blank between opposite holding surfaces of a fixture, causing a firm abutment and retaining action on the longitudinal side surface portions of the key blank located adjacent to and all along said profile groove being formed, whereby the key blank material adjacent to said profile groove is retained in a fixed state without being deformed during the punching operation.
Correspondingly, an apparatus according to the invention comprises
a longitudinally guided punching or broaching tool with at least one cutting tooth for forced movement longitudinally along the key blank and cutting out said profile groove in the key blank during a punching or broaching operation,
a fixture provided with a guiding device for longitudinally guiding said punching or broaching tool during said punching or broaching process, and
a holding device in said fixture, said holding device having two opposite holding surfaces adapted to abut against two opposite, longitudinal side surface portions of said key blank during said punching or broaching operation, causing an abutment and retaining action on the longitudinal side surface portions located adjacent to and all along said profile groove being formed, whereby the key blank material adjacent to said profile groove is retained in a fixed state without being deformed during said punching or broaching operation.
Preferably, the punching or broaching tool is secured to a slide member which is forced and guided rectilinearly in relation to the fixture. The slide member may be guided in a longitudinal recess in the fixture, such as a cavity communicating with a longitudinal passageway leading out to the holding surface of the fixture abutting against a side or edge surface of the key blank. The slide member may be provided with a neck portion extending through such a passageway and carrying the punching or broaching tool.
The profile groove may be formed by a combination of processes, such as an initial forming with a rotating cutting disc and a final forming with a punching or broaching tool. However, it is also possible to form the whole profile groove in one processing step by means of the punching or broaching tool.
The punching or broaching tool may be provided with only one cutting tooth, or be constituted by a broach having two or more cutting teeth.
The profile groove being formed may be located in a side surface or in an edge surface of the key blank.
These and other features of the invention will be apparent from the detailed description below and from the appended claims.
The invention will now be explained in detail below with reference to the drawings illustrating some preferred embodiments.
The apparatus shown in
As appears from
In the lower position of the movable block 20, as shown in
While being held firmly in its position between the two blocks 10, 20, the key blank will be cut by a punching or broaching tool 30 secured to a linearly guided slide member 40. During the cutting process, a profile groove 4 is formed in the key blank, adjacent to its first or lower side surface 2. In this way, a pre-formed groove 4 of rectangular shape will be extended sideways or downwardly (to the right in
The undercut portion of the groove 4a extends only along the key blade up to the stopping step surface 5 near the gripping portion 6, along a length L1. Thus, in this embodiment, the undercut portion 4a will end with a distinct step surface inside the profile groove 4, whereas the remaining profile groove will end with a curved portion, corresponding to the shape of the cutting disc used when forming the rectangular initial groove 4. The innermost, undercut portion 4a of the profile groove may be used to achieve an axial stop, cooperating with a corresponding rib with a limited length in an associated key plug of a cylinder lock (not shown).
In this embodiment (
The forces appearing when cutting the key blade by the punching or broaching tool 30 are very great, and it is imperative that the key blank is held firmly between the blocks 10, 20 and also that the linear guidance of the slide member 40 is very precise. The exact guidance of the slide member 40 is accomplished by way of machining or otherwise forming a longitudinal cavity 15 in the lower block 10 (
The punching or broaching tool 30 must be firmly secured to the slide member 40, and this is achieved by a longitudinally extending neck portion 41 which is adapted to connect the slide member 40 with the punching or broaching tool 30 and which fits with a slight play in a longitudinal passageway 16 (
Preferably, the slide member 40 and the cutting tool are made in one piece, but it is also possible to weld or screw them together.
In
In case the profile groove 4 is to be provided with a further undercut portion, it is feasible to use a modified punching or broaching tool having at least one further tooth having a configuration corresponding to the desired shape of the further undercut portion 4aa, as shown in
In this case, the profile groove 4 extends along the whole length of the key blade and along the major part of the gripping portion 6, along a total length L2 up to a hole in the gripping portion.
Another key blank is shown in
In
The height of the upstanding side portions 12′, 13′ is substantially the same as (or slightly less than) the thickness of the key blank 1, so that the key blade 1 will be firmly held in place by the upper block 20′ when the latter is pressed down. Then, the planar lower surface (not visible in
The structure and function of the punching or broaching tool 30 and the slide member 40 are the same in this embodiment as in the previous one. The only difference is the configuration of the two blocks 10, 20 and 10′, 20′, respectively.
Of course, a key blank formed as described above is not a finished key. Rather, as is well-known in the art, it should be provided with some code pattern cooperating with tumblers in an associated cylinder lock (not shown). Such codes can be formed e.g. along the profile groove, so as to cooperate with side tumblers in the lock, and/or at a longitudinal edge 7, as shown in
As indicated above, it is also possible to form an under-cut profile groove in one manufacturing step by using a broach having a number of cutting teeth. Various resulting key blanks are shown in
Depending on the shape of the profile groove, the broach 30′ is provided with a number of teeth 31′, 32′, 33′, 34′, etc. (see
An advantage with the embodiment shown in
The invention may be implemented in various ways. An alternative groove making apparatus is shown in
Otherwise, this apparatus, with the slide member 40 and the punching or broaching tool 30, operates basically in the same way as in the previous embodiments.
Although not shown in the drawings, the cavity 15 which guides the slide member 40 may be formed as an open recess in the lower block 10, preferably with undercut side portions serving to hold the edge portions of the slide member in place vertically, or it may be a circumferentially closed cavity. In the latter case, the key blank will have to be inserted into the cavity as well, possibly together with an insert member fitting precisely into the cavity together with the key blank. In such a case, there will be no movable block of the fixture, other than the insert member which is positioned axially into the cavity. It seems more practical, however, to have two blocks, one of which is movable vertically or transversely in relation to the other.
It may be possible to use a fixture with only one block having a recess at the top, with a seating surface for one (lower) side of the key blank, and longitudinal gripping teeth or ribs which engage with portions of the other (upper) side of the key blank. The risk of floating material on this upper side is lower, so such a fixture may also be useful, at least in case the profile groove in said one (lower) side of the key blank is rather shallow, e.g. less than half of the thickness of the key blade.
The key blank 1 may have a grip portion 6a, as shown in
The exact shape of the profile groove may be selected as desired. There may be minor irregularities in the cross-sectional configuration, and it is also possible to leave rather thin walls between an undercut portion of the profiled groove, internally of a ridge portion, and the external side of such a ridge portion (which may form a part of side surface of the key blank).
In particular, it is possible to form profile grooves having any geometrical shape as disclosed in the international patent application published in WO2010/096009 (WINLOC AG).
Thus, the inventive method and apparatus will give a wide freedom in designing new keys for cylinder locks, with one or more profile grooves with or without an undercut groove portion.
Also, with a broach having a multitude of teeth, it is possible to cut a complicated shape of a profile groove in a single manufacturing step, which makes the production quick and not very expensive, at least when producing large number of key blanks.
Number | Date | Country | Kind |
---|---|---|---|
1250875 | Jul 2012 | SE | national |
The present application is a Continuation Application of U.S. patent application Ser. No. 14/415,488 filed on Jan. 16, 2015, which is a National Phase of PCT Patent Application No. PCT/SE2013/050669, filed on Jun. 11, 2013, which claims priority to Swedish Patent Application No. 1250875-0 filed Jul. 18, 2012, the entire contents of each are hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
4453432 | Widen | Jun 1984 | A |
5127532 | Cimino | Jul 1992 | A |
5688085 | Watts | Nov 1997 | A |
5715717 | Widen | Feb 1998 | A |
6413024 | Chen | Jul 2002 | B1 |
8287215 | Freeman | Oct 2012 | B2 |
8919160 | Piotrowski | Dec 2014 | B2 |
20060147289 | Gimelfarb et al. | Jul 2006 | A1 |
20110271723 | Widén | Nov 2011 | A1 |
20110289990 | Piotrowski et al. | Dec 2011 | A1 |
20150224584 | Parillo | Aug 2015 | A1 |
Number | Date | Country |
---|---|---|
500 638 | Jul 2006 | AT |
10029113 | Jan 2002 | DE |
0737265 | Oct 1996 | EP |
2301053 | Nov 1996 | GB |
S57-052532 | Mar 1982 | JP |
10-137883 | May 1998 | JP |
WO 2010095997 | Aug 2010 | WO |
Entry |
---|
Extended European Search Report for corresponding European Application No. 13819787.6 dated Mar. 7, 2016. |
Number | Date | Country | |
---|---|---|---|
20180154467 A1 | Jun 2018 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 14415488 | US | |
Child | 15880093 | US |