Profiled key for cylinder locks

Abstract

A key for use in a cylinder lock with a rotatable key plug having a profiled keyway. The key comprises an elongated, substantially flay key blade (120; 120′) having a longitudinal profile groove (122; 122′) extending along at least a portion of the length of the key blade. The groove has an undercut portion (129) adjacent to a ridge portion (128, 128′), the outside of which forms part of a side surface (123; 123′) of the key blade. The undercut portion (129; 129′) of the groove is expanded, at its innermost part adjacent to and inside said ridge portion, into a longitudinally extending pocket (135; 135′).

Description

locking pins 14 in an upper portion thereof and a rotatable key plug 12 accommodated in a cylindrical bore of the housing. In the key plug 12, there is a central longitudinal keyway or key hole 13 having a sectional profile corresponding to an associated key 20 provided with conventional recesses 21 at the upper edge thereof and a profile groove 22 at a side surface 23 of the key blade. As appears from FIG. 3, the key also has a grip portion 24.

The operation of the lock is more readily understood from the cross-sectional view in FIG. 4. The key plug 12 is rotatable within the housing 11 and can be locked against rotation by means of a longitudinal row of upper and lower locking pins 14a, 14b. Each pair of such locking pins can be positioned with their abutting end surfaces at the shear line between the key plug 12 and the housing 11. In this position, as shown in FIG. 4, the key plug 12 is rotatable. Here, as is well-known in the art, the locking pins are positioned so as to release the lock by means of a properly cut key 20.

The full profile of the key 20 (of prior art design) is illustrated in FIG. 5, as disclosed e.g. in the above-mentioned U.S. Pat. No. 5,715,717 (Widén). Accordingly, this prior art key has a longitudinal profile groove 22 extending longitudinally along the key blade at a depth which is slightly greater than half the thickness of the key blade. In FIG. 5, the central a plane of the key blade is denoted by the letter “A”. The longitudinal groove 22 has an inner wall 24 surface 241 and opposite walls upper wall surface 25 and lower side wall surface 26. An inclined portion 25a extends upwardly from the upper wall surface 25. One of these opposite walls the wall surfaces, in particular the lower side wall or surface 26 located closest to the base edge 27 of the key blade is undercut and extends in a plane being inclined so as to face inwardly towards the bottom inner wall or surface 24 241. This lower side wall surface 26 of the undercut groove 22 forms an inside wall surface of a ridge portion 28, the outside of which forms part of the above mentioned side surface 23 of the key blade.

The prior art key blade shown in FIGS. 2, 3, 4 and 5 also has two further longitudinal grooves 30 and 31 on the other side of the key (to the left in FIG. 5).

The undercut portion 29 of the longitudinal groove 22 has many advantages, as explained in the above-mentioned U.S. Pat. No. 5,715,717 (Widén), especially with regard to increasing the number of possible profile variations, improved resistance against picking the lock and high security against unauthorized key copying.

According to the present invention and as illustrated in FIGS. 6 through 9, a further improvement resides in a modification of the undercut groove. This modification comprises an expansion or extension of the innermost part of the undercut portion of the groove 122 (FIG. 7) so as to form a longitudinal pocket-like configuration 135. In these Figures, all reference numerals relating to the key correspond to those shown in FIG. 5, although they have been supplemented with the digit “1” before the number given in FIG. 5.

The As illustrated in FIG. 7, the downwardly extended pocket-like configuration 135 of the modified undercut groove 122, is (in this particular embodiment) substantially rectangular in cross-section, with opposite lateral walls 132 and 133 being parallel to each other, and a lowermost transverse end wall 134, being parallel to the lower edge surface 127 of the key blade and facing upwardly in the direction of the central plane A of the key blade. The flat key blade 120 has an external side wall surface 123 at the lower part of the flat one piece key blade 120 lying substantially in the same plane as an upper side surface 1123′ of the flat one piece key blade 120 at an upper part thereof, above said longitudinal profile groove 122.

The innermost lateral wall 132 of the pocket-like extension 135 adjoins with the inner wall 124 of the undercut groove, but is slightly displaced inwardly (away from the groove opening) so as to form a step 136, whereas the opposite lateral wall 133 forms the inside wall of the ridge portion 128, in parallel to the external side surface 123 of the key blade.

Thus, the surfaces 123, 133 and 132 are substantially parallel to each other. The key blade 120 is a flat one piece key blade with an undercut portion 129 of the longitudinal profile groove 122 which, at an innermost part, is extended further substantially in the same direction as the vertical direction (VD) into a longitudinal, substantially uniformly wide pocket (135) having a uniform width with opposite inner and outer substantially parallel lateral wall surface portions (132, 133). The undercut portion or longitudinal profile groove 122 is defined at an upper part thereof by a smallest opening width (w), as seen perpendicularly to the external side wall surface 123 of the lower portion of said flat one piece key blade 120 between an upper wall 160 and the ridge portion 128. The vertical dimension (h) of the ridge portion 128 is equal to or greater than half of said smallest opening width (w). The inner wall surface 124 of said longitudinal profile groove 122 is located at a distance from the external side wall surface 123 of the flat one piece key blade 120 which is greater than half the thickness of the flat one piece key blade 120.

According to a first aspect of the invention, the undercut portion 129 of the longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface 1123′ and the external side wall surface 123 of the flat one piece key blade 120. The undercut portion 129 of the longitudinal profile groove 122, at an innermost part, is extended further, substantially in the same direction as the vertical direction (VD) into a longitudinal, substantially uniformly wide pocket 135 having a uniform width with opposite inner and outer substantially parallel lateral wall surface portions 132, 133 wherein the inner wall surface 124 of the longitudinal profile groove 122 adjoins the inner lateral wall surface portion 132 of the pocket 135 and the inner lateral wall surface 132 of the pocket 135 extends downwardly to a lowermost transverse end wall surface 134, which is substantially flat or slightly curved, and which is substantially parallel to a lowermost edge wall surface 127 of the key blade and which faces upwardly in a direction opposite to the vertical direction (VD) towards the upper wall surface of the longitudinal profile groove 122 with the opposite lateral wall surface portions 132, 133 of the pocket 135 being substantially parallel to the upper side wall surface 1123″ and the external side wall surface 123 of the flat one piece key blade 120.

According to a second aspect of the invention, the undercut portion 129 of the longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface 1123′ and the external side wall surface 123 of the flat one piece key blade 120. The undercut portion 129 of the longitudinal profile groove 122, at an innermost part, is extended further, substantially in the same direction as the vertical direction (VD) into a longitudinal, widened pocket 135 having a larger lateral width than the narrowest part of the undercut portion 129 of the longitudinal profile groove 122, said widened pocket 135 being formed by opposite inner and outer lateral wall surface portions 132, 133, and said inner wall surface 124 of said longitudinal profile groove 122 adjoins, by way of a continuously downwardly extending wall surface portion 136, said inner lateral wall surface portion 132 of the pocket 135 and the inner lateral wall surface portion 132 of the pocket 135 extends continuously further downwardly to a lowermost transverse end wall surface 134, wherein the highest point of said inner lateral wall surface portion 132 is located below the lowest point of said inner wall surface 124 of said longitudinal profile groove 122, and the lowermost transverse end wall surface 134 which faces upwardly in a direction opposite to the vertical direction (VD) towards the upper wall surface of the longitudinal profile groove 122.

According to a third aspect of the invention, the undercut portion 129 of the longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface 1123′ and the external side wall surface 123 of the flat one piece key blade 120. The undercut portion 129 of the longitudinal profile groove 122, at an innermost part, is extended further, substantially in the same direction as the vertical direction (VD) into a longitudinal pocket being interrupted by at least one longitudinal recess 132a formed in at least one of opposite inner and outer lateral wall surface portions 132, 133 wherein the inner wall surface 1243 of the longitudinal profile groove 122 adjoins the inner lateral wall surface portion 1324, located opposite to the ridge portion and the inner lateral wall surface portion 1324 extends downwardly to a lowermost transverse end wall surface 134, the lowermost transverse end wall surface 134 being substantially flat or slightly curved and being substantially parallel to a lowermost edge wall surface 127 of the key blade and which faces upwardly in a direction opposite to the vertical direction (VD) towards the upper wall surface of the longitudinal profile groove 122 with the opposite lateral wall surface portions 132, 133 of the pocket 135 being substantially parallel to the upper side wall surface 1123″ and the external side wall surfaces 123 of the flat one piece key blade 120.

The ridge portion 128 is somewhat longer, measured in parallel to the central plane A of the key blade, than the prior art structure (FIG. 5). More particularly, the ridge portion 128 has a vertical dimension h, which is more than half of the smallest opening width w of the undercut groove 122, this smallest opening width w being measured as a perpendicular projection onto the bottom inner wall 124 of the longitudinal groove 122. Also, preferably, the vertical dimension h of the ridge portion 128 is greater than the distance d between the lowermost transverse end wall 134 and the lower edge surface 127 of the key blade. In this embodiment, the vertical dimension h of the ridge portion 128 is equal to or greater than the smallest opening width w. This structure is advantageous for several reasons:

• • by varying the width, depth (in the plane A) and longitudinal extension of the pocket-like configuration, the profile shape can be varied considerably;
  • because of the opposite lateral wall portions 132, 133 the total width of the undercut portion of the profile groove 122 can be accommodated in a limited region laterally, so that the total width of the key blade can be kept rather small. It appears from FIGS. 5 and 7 that the total width of the new key blade is about the same;
  • the corresponding tongue portion, which may form a part of a longitudinal rib 150 at a side wall of the key way (see FIGS. 8 and 9), will be stronger and does not have to have a pointed or sharp end portion, as in the prior art structure (compare FIG. 4);
  • the pocket-like extension 135 of the undercut portion of the groove 122 will make it much more difficult to make copies of such keys, since it is not sufficient to use only a cutter disk. Normally, other tools also have to be used. Accordingly it will be difficult for others than specialized manufacturers to produce such key blanks;
  • the relatively long vertical extension of the ridge portion 128, in parallel to the central plane A of the key blade, will make it possible to cut rather deep recesses in the ridge portion. Accordingly, just like in the prior art embodiment of FIGS. 1-5, it is possible to provide many vertical levels of code recesses in this material region, see FIG. 6. Of course, this will also facilitate lock and key systems having a very high number of code combinations.

In FIGS. 8 and 9 there is shown an embodiment with a side locking tumbler 105, which is guided in a cylindrical cavity 106 in the rotatable key plug 112. In principle, the arrangement is similar to those disclosed in the U.S. Pat. Nos. 4,756,177 (Widén) and 5,715,717 (Widén).

The parts that correspond to the previous, prior art embodiment (FIG. 5 FIGS. 1-5) have been given the same reference numerals, with the digit “1” added before the numbers shown in FIG. 5 4.

Accordingly, the side tumbler 105 is rotatable around its cylindrical axis, so that a transversally projecting finger 105a will pivot back and forth when the projecting finger 105a follows a wave-like coded surface on the side of the key blade (see FIG. 6), in this case in the ridge portion 128 (see FIG. 7). When the side tumbler 105 is correctly positioned, a recess 105b in its cylindrical surface will register with corresponding projections 108a on a side bar 108 (FIG. 9). In this way, the side bar may move radially inwards so as to permit rotation of the key plug 112.

The projecting finger 105a on the side tumbler 105 will contact the wave-like code pattern on the side of the key blade 120, as shown in FIG. 6, while pivoting back and forth and also moving vertically up and down. When the key blade is fully inserted, the various side tumbler projections 105a will be located in the concavities 102a, 102b, 102c, 102d, 102e and possibly also (or alternatively) onto an upper code surface portion 102f at an uppermost extra code level. Such an upper, extra code level is disclosed in the published international patent application WO2005/028789 (Winloc et al).

It would be possible to provide an even deeper pocket-like extension 135 of the undercut portion of the profile groove, in parallel to the central vertical plane A of the key blade. Then, the number of possible code levels in the ridge portion 133 128 (see FIGS. 6 and 7) would be larger than in prior art structures.

It should be noted that the new configuration of the undercut groove 122, with the pocket-like extension 135, is useful even without having a side tumbler 105. Then, the ridge portion is basically continuous and does not have any cuts or codes.

Also, if at least one side tumbler is used, it does not have to be rotatable, but can be guided for elevational movement only. Furthermore, the side tumbler does not have to operate as a locking means for locking the key plug against rotation. Alternatively, it may serve only as a blocking element, which prevents incorrectly cut keys from being fully inserted into the key way 13 of the lock 10. Such a blocking element is disclosed in a patent application being filed by the same applicant on the same day as the earliest priority date of this application.

The exact configuration or shape of the longitudinally extending pocket may be modified in various ways within the scope of the present invention. In FIG. 10, there is shown an embodiment where the inner wall 124 surface 124′ of the longitudinal profile groove 122 122′ of the key blade 120′ merges smoothly with the adjoining inner lateral wall 132 surface 132′ of the vertically oriented pocket-like configuration 135 135′ which is uniformly wide, without any lateral step (136 in FIG. 7).

In FIG. 11, the pocket-like configuration 135 135″ is similar to the one in FIG. 7, but the lowermost transverse end wall surface 134′ is rounded or curved. In addition, FIG. 11 illustrates the undercut portion 129′.

The embodiment shown in FIG. 12 includes a lower side wall 126′ and is similar to the one embodiment in FIG. 11, but the lowermost transverse end wall surface 134″ is shorter (but still curved), and the inner wall 124 surface 124″ of the groove merges smoothly with the adjoining inner lateral wall 132 surface 132″ (as in FIG. 10). In FIGS. 11 and 12 the lowermost transverse end wall surfaces 134′, 134″ of the pocket 135 are curved.

In FIG. 13, the pocket-like configuration 135′ 1353 is modified into a circular cross-section. Accordingly, in this embodiment, the lateral walls 132, 133 wall surfaces 1323, 133′ and the lowermost end wall 134 surface 1343 are all formed as circular arcs merging with each other.

The embodiment shown in FIG. 14 is like the one shown in FIG. 10, but the inner lateral wall 132 surface 1324 adjoining the inner wall 124 surface 1243 is provided with a longitudinal recess 132a, which is rectangular in cross-section.

The embodiment of FIG. 15 is similar to the one of FIG. 14, but there is also a longitudinal recess 133a in the outer lateral wall 133 133″ opposite to the longitudinal recess 132a 132a′ in the lateral wall 1325.

The embodiment in FIG. 16 is similar to the one in FIG. 15, but there is a longitudinal rib 133b (instead of a recess 133a) opposite to the longitudinal recess 132a 132a″.

The modified embodiment shown in FIG. 17 comprises relatively small longitudinal recesses 132c, 133c, 134c with part cylindrical part-cylindrical cross-sections in the lateral walls 133 wall surfaces 1333 and 132 1326 and the lowermost end wall 134 surface 1344, respectively. Except for these part-circular recesses, this embodiment corresponds to the one shown in FIG. 7.

The embodiments of FIGS. 14 through 17 are included to illustrate that the opposite lateral wall surface portions and the lowermost transverse end wall surface of the longitudinal pocket may be provided with irregular surface portions.

The key blade 120″ shown in FIG. 18 is composed of a lower part 150″, which is identical or similar to the lower parts of the key blades shown in FIGS. 10-17, and an upper part 151″, which is identical to the lower part 150″, but turned upside down. In this way the key blade 150″, 151″ can be inserted either way into an associated key hole, either as shown in FIG. 18 or turned upside down (the profile is then exactly the same because of the symmetry of the lower and upper parts). The key blade 120″ includes a wall surface 140 and an upper and lower pocket-like extension 1354.

Finally, FIGS. 19 through 27 26 show modified embodiments similar to those shown in FIGS. 10 through 17. Thus, the keys 321 through 329 328 each have a cross-sectional profile corresponding to those shown in FIGS. 10 through 17, respectively, except that the upper part of the ridge portion 228 is portions 228′, 228″, 2283, 2284, 2285, 2286, 2287 and 2288 are uniformly thick, and the inside 226 226′, 226″, 2263, 2264, 2265, 2266, 2267 and 2268 thereof is are parallel to the central plane of the key blade.

FIG. 27 includes a key 330 and corresponds to FIG. 18, and FIG. 28 includes a key 331 and corresponds to FIGS. 11 and 20, except that the lowermost transverse end wall 234 surface 1234 is flat. In addition, in FIG. 27 the ridge portion is identified by 2289 and the inside by 2269. Further, in FIG. 28, the ridge portion is identified by 1228 and the inside by 1226.

In all embodiments described above, and in the appended claims, it is assumed that the inner wall 124 of the longitudinal undercut groove 122, 122′, 122″ is substantially parallel to the central plane A of the key blade and a side surface the external side wall surfaces 123, 123′, 123″ thereof. Within this definition, the inner wall may be oriented at a small angle to said central plane A, this angle being normally no more than 15 15°, in some cases (such as a relatively thick key blade) somewhat larger.

The longitudinally extending pocket may be shorter than the length of key blade and extend along only a portion thereof.

Also, the longitudinal profile rib at the key plug may be interrupted or formed as one or more separate elements mounted in the key plug.

Claims

1. The A key for use in a cylinder lock with a rotatable key plug having a profiled key way, said key comprising:

an elongated, substantially flat one piece key blade (120) having a longitudinal profile groove (122) extending along at least a portion of the length of the flat one piece key blade (120), with an inner wall surface (124) of said groove being substantially parallel to a an external side wall surface (123) of said flat key blade,

said longitudinal profile groove (122) having, at a lower part thereof, an undercut portion (129) adjacent to and inside a ridge portion (128) of the flat one piece key blade (120), the outside of said ridge portion (128) forming a part of said external side wall surface (123) of the flat one piece key blade (120),

said external side wall surface (123) at the a lower part of said flat one piece key blade (120) lying substantially in the same plane as a an upper side wall surface (1123′) of the flat one piece key blade (120) at an upper part thereof, above said longitudinal profile groove (122),

said longitudinal profile groove (122) defining, at an upper part thereof, a smallest opening width (w), as seen perpendicularly to said external side wall surface (123) of said lower portion of said flat one piece key blade (120), between an upper wall surface (160) and said ridge portion (128), and

the inside of said ridge portion facing (128) being opposite said inner wall surface (124) of said longitudinal profile groove (122), wherein:

said undercut portion (129) of said longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface (1123′) and the external side wall surface (123) of the flat one piece key blade (120),

said undercut portion (129) of said longitudinal profile groove (122), at its an innermost part inside said ridge portion (128), is extended further, substantially in a the same direction as said vertical direction in parallel to said upper and lower side surfaces (123) of the key blade (120), (VD) into a longitudinal, substantially uniformly wide pocket (135) having a uniform width with opposite inner and outer substantially parallel lateral wall surface portions (132, 133) and wherein said inner wall surface (124) of said longitudinal profile groove (122) adjoins the inner lateral wall surface portion (132) of said pocket (135) and said inner lateral wall surface (132) of said pocket (135) extends downwardly to a lowermost transverse end wall surface (134), which is substantially flat or slightly curved, and which is substantially parallel to a lower lowermost edge portion wall surface (127) of the key blade and which faces upwardly in a direction in a central plane (A) of the key blade opposite to said vertical direction (VD) towards said upper wall surface of said longitudinal profile groove (122) with said opposite lateral wall surface portions (132, 133) of said pocket (135) being substantially parallel to said upper side wall surface (1123″) and lower the external side surfaces wall surface (123) of the flat one piece key blade (120).

2. The key as defined in claim 1, wherein the a vertical dimension (h) of said ridge portion (128) is greater than the distance (d) between said lowermost transverse end wall surface (134) and said lower lowermost edge wall surface (127) of the flat one piece key blade (120).

3. The key as defined in claim 1, wherein said pocket (135) has a substantially rectangular cross-section.

4. The key as defined in claim 1, wherein said inner wall (124) surface (124′) of said longitudinal profile groove (122) (122′) merges with one of said opposite lateral walls wall surface portions (132, 133) (132′) of said pocket.

5. The key as defined in claim 1, wherein the a vertical dimension (h) of said ridge portion (128), measured in said plane of said lower external side wall surface (123) and upper side wall surface (123) (1123′) of the flat one piece key blade (120), is more than half of the said smallest opening width (w) of said longitudinal profile groove (122) adjacent to said external side wall surface (123), said smallest opening width (w) being measured as a perpendicular projection onto said inner wall surface (124) of said longitudinal profile groove (122).

6. The key as defined in claim 5, wherein said vertical dimension (h) of said ridge portion (128) is equal to or greater than said smallest opening width (w).

7. The key as defined in claim 1, constituting wherein the flat one piece key blade (120) is formed from a key blank with a continuous upper edge portion configured so as to permit coded recesses to be cut therein.

8. The key as defined in claim 1, having coded recesses (102a . . . 102e) cut into said ridge portion (128), so as to form a side code on the flat one piece key blade (120), said side code recesses being configured to cooperate with at least one side tumbler (105) in an associated lock.

9. The key as defined in claim 8, wherein said side code recesses (102a . . . 102e) forming a side code constitute a wave-like, longitudinal code pattern.

10. The key as defined in claim 8, wherein said side code recesses (102a . . . 102e) are cut into the whole material thickness of said ridge portion (128), so that the side code recesses reach all the way from the outside external side wall surface (123) of said ridge portion (128) into said longitudinal pocket (135) of the undercut profile groove (122).

11. The key as defined in claim 8, wherein said side code recesses (102a . . . 102e) are cut from an upper edge of the ridge portion (128) down to various levels between said upper edge and the a lowermost part of said longitudinally extending pocket (135).

12. The key as defined in claim 8, wherein said side code recesses (102a . . . 102e) form concavities with lower bottom portions located at a number of different levels, each representing a code.

13. The key as defined in claim 11, wherein said different levels also include an uppermost level at the upper edge (1021) of said ridge portion (128).

14. The key as defined in claim 11, wherein the number of different levels is at least three.

15. The key as defined in claim 1, wherein the inner wall surface (124) of said longitudinal profile groove and the adjoining longitudinal pocket (135) are is located at a depth distance from said external side wall surface (123) of the flat one piece key blade (120) which is greater than half the thickness of said flat one piece key blade (120).

16. The key as defined in claim 1, wherein said substantially flat one piece key blade (120″) has an upper and lower portions (151″, 150″), each portion (151″) having an undercut groove (122″) portion with said an innermost longitudinal pocket (135″) (1354), such that the key is symmetrical and can be inserted either way into an associated keyway of said cylinder lock.

17. The A key for use in a cylinder lock with a rotatable key plug having a profiled key way, said key comprising:

an elongated, substantially flat one piece key blade (120) having a longitudinal profile groove (122) extending along at least a portion of the length of the flat one piece key blade (120), with an inner wall surface (124) of said longitudinal profile groove (122) being substantially parallel to a to an external side wall surface (123) of said flat key blade,

said longitudinal profile groove (122) having, at a lower part thereof, an undercut portion (129) adjacent to and inside a ridge portion (128) of the flat one piece key blade (120), the outside of said ridge portion forming a part of said external side wall surface (123) of the flat one piece key blade (120),

said external side wall surface (123) at the a lower part of said flat one piece key blade (120) lying substantially in the same plane as a side an upper sidewall surface (1123′) of the flat one piece key blade (120) at an upper part thereof, above said longitudinal profile groove (122),

said longitudinal profile groove (122) defining, at an upper part thereof, a smallest opening width (w) as seen perpendicularly to said external side wall surface (123) of said lower portion of said flat one piece key blade (120), between an upper wall surface (160) and said ridge portion (128), and

the inside of said ridge portion facing (128) being opposite said inner wall surface (124) of said longitudinal profile groove (122), wherein:

said undercut portion (129) of said longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface (1123′) and the external side wall surface (123) of the flat one piece key blade (120),

said undercut portion (129) of said longitudinal profile groove (122), at its an innermost part inside said ridge portion (128), is extended further, substantially in a the same direction as said vertical direction in parallel to said upper and lower side surfaces (123) of the key blade (120), (VD) into a longitudinal, substantially bulbous wide longitudinal widened pocket (135) having a larger lateral width relative to than a narrowest part of the longitudinal undercut portion (129) of the profile groove (122), said bulbous wide widened pocket (135) being formed by opposite inner and outer lateral wall surface portions (132, 133), and said inner wall surface (124) of said longitudinal profile groove (122) adjoins, by way of a continuously downwardly extending wall surface portion (136), said inner lateral wall surface portion (132) of the pocket (135) and the inner lateral wall surface portion (132) of the pocket (135) extends continuously further downwardly to a lowermost transverse end wall surface (134), wherein the highest point of said inner lateral wall surface portion (132) is located below the lowest point of said inner wall surface (124) of said longitudinally profile groove (122), and a the lowermost transverse end wall surface (134) which is slightly curved and faces upwardly in a direction in a central plane (A) of the key blade opposite to said vertical direction (VD) towards said upper wall surface of said longitudinal profile groove (122).

18. The key as defined in claim 17, wherein the a vertical dimension (h) of said ridge portion (128) is greater than the distance (d) between said lowermost transverse end wall surface (134) and said lower a lowermost edge wall surface (127) of the flat one piece key blade (120).

19. The key as defined in claim 17, wherein at least one of said opposite lateral wall surface portions (132, 133) is curved.

20. The key as defined in claim 17, wherein said lowermost transverse end wall (134′, 134″) of said pocket (135) is curved with a radius being more than half of the width of said pocket, said width being measured transversely to said side surface (123) of said key blade (120).

21. The key as defined in claim 17, wherein said inner wall (124) surface of said longitudinal profile groove (122) merges with one of said opposite lateral walls wall surface portions (132, 133) (1323) of said pocket.

22. The key as defined in claim 17, wherein the a vertical dimension (h) of said ridge portion (128), measured in said plane of said lower external side wall surface (123) and said upper side wall surface (123) (1123′) of the flat one piece key blade (120), is more than half of the said smallest opening width (w) of said longitudinal profile groove (122) adjacent to said external side wall surface (123), said smallest opening width (w) being measured as a perpendicular projection onto said inner wall surface (124) of said longitudinal profile groove (122).

23. The key as defined in claim 15 17, wherein said a vertical dimension (h) of said ridge portion (128) is equal to or greater than said smallest opening width (w).

24. The key as defined in claim 17, constituting wherein the flat one piece key blade (120) is formed from a key blank with a continuous upper edge portion configured so as to permit coded recesses to be cut therein.

25. The key as defined in claim 17, having coded recesses (102a . . . 102e) cut into said ridge portion (128), so as to form a side code on the flat one piece key blade (120), said side code recesses being configured to cooperate with at least one side tumbler (105) in an associated lock.

26. The key as defined in claim 25, wherein said side code recesses (102a . . . 102e) forming a side code constitute a wave-like, longitudinal code pattern.

27. The key as defined in claim 25, wherein said side code recesses (102a . . . 102e) are cut into the whole material thickness of said ridge portion (128), so that the side code recesses reach all the way from the outside external side wall surface (123) of said ridge portion (128) into said longitudinal pocket (135) of the undercut profile groove (122).

28. The key as defined in claim 25, wherein said side code recesses (102a . . . 102e) are cut from an upper edge of the ridge portion (128) down to various levels between said upper edge and the a lowermost part of said longitudinally extending pocket (135).

29. The key as defined in claim 25, wherein said side code recesses (102a . . . 102e) form concavities with lower bottom portions located at a number of different levels, each representing a code.

30. The key as defined in claim 28, wherein said different levels also include an uppermost level at the upper edge (102f) of said ridge portion (128).

31. The key as defined in claim 28, wherein the number of different levels is at least three.

32. The key as defined in claim 17, wherein the inner wall surface (124) of said longitudinal profile groove and the adjoining longitudinal pocket (135) are is located at a depth distance from said external side wall surface (123) of the flat one piece key blade (120) which is greater than half the thickness of said flat one piece key blade (120).

33. The key as defined in claim 17, wherein said substantially flat one piece key blade (120″) has an upper and lower portions (151″, 150″), each portion (151″) having an undercut groove (122″) with said innermost longitudinal pocket (135″) (1354), such that the key is symmetrical and can be inserted either way into an associated keyway of said cylinder lock.

34. The A key for use in a cylinder lock with a rotatable key plug having a profiled key way, said key comprising:

an elongated, substantially flat one piece key blade (120) having a longitudinal profile groove (122) extending along at least a portion of the length of the flat one piece key blade (120), with an inner wall surface (124) of said groove being substantially parallel to a external side wall surface (123) of said flat key blade,

said longitudinal profile groove (122) having, at a lower part thereof, an undercut portion (129) adjacent to and inside a ridge portion (128) of the flat one piece key blade (120), the outside of said ridge portion forming a part of said external side wall surface (123) of the flat one piece key blade (120),

said external side wall surface (123) at the lower part of said flat one piece key blade (120) lying substantially in the same plane as a an upper side wall surface (1123′) of the flat one piece key blade (120) at an upper part thereof, above said longitudinal profile groove (122),

said longitudinal profile groove (122) defining, at an upper part thereof, a smallest opening width (w), as seen perpendicularly to said external side wall surface (123) of said lower portion of said flat one piece key blade (120), between an upper wall surface (160) and said ridge portion (128), and

the inside of said ridge portion facing (128) being opposite said inner wall surface (124) of said longitudinal profile groove (122), wherein:

said undercut portion (129) of said longitudinal profile groove extends downwardly substantially in a vertical direction (VD) in parallel to the upper side wall surface (1123′) and the external side wall surface (123) of the flat one piece key blade (120),

said undercut portion (129) of said longitudinal profile groove (122), at its an innermost part inside said ridge portion (128), is extended further, substantially in a the same direction as said vertical direction in parallel to said upper and lower side surfaces (123) of the key blade (120), (VD) into a longitudinal, substantially uniformly wide pocket (135) having being interrupted by at least one longitudinal recess (132a) formed in at least one of opposite inner and outer lateral wall surface portions (132, 133) and wherein said inner wall surface (1243) of said longitudinal profile groove (122) adjoins the inner lateral wall surface portion (1324), located opposite to said ridge portion and said inner lateral wall surface portion (1324) extends downwardly to a lowermost transverse end wall surface (134), said lowermost transverse end wall surface (134) being substantially flat or slightly curved and being substantially parallel to a lower lowermost edge portion wall surface (127) of the key blade and which faces upwardly in a direction being parallel to a central plane (A) of the key blade opposite to said vertical direction (VD) towards said upper wall surface of said longitudinal profile groove (122) with said opposite lateral wall surface portions (132, 133) of said pocket (135) being substantially parallel to said upper side wall surface (1123″) and lower the external side wall surfaces (123) of the flat one piece key blade (120).

35. The key as defined in claim 34, wherein the a vertical dimension (h) of said ridge portion (128) is greater than the distance (d) between said lowermost transverse end wall surface (134) and said lower lowermost edge wall surface (127) of the flat one piece key blade (120).

36. The key as defined in claim 34, wherein at least one of said opposite lateral wall portions (132, 133) is curved.

37. The key as defined in claim 34, wherein said lowermost transverse end wall surface (134′, 134″) of said pocket (135) is curved with a radius being more than half of the width of said pocket, said width being measured transversely to said external side wall surface (123) of said flat one piece key blade (120).

38. The key as defined in claim 34, wherein at least one of said longitudinal recess recesses formed in at least one of the opposite lateral wall surface portions (132) and said lowermost transverse end wall surface (134) is provided with an irregular surface portion (132c, 134c).

39. The key as defined in claim 34, wherein said inner wall (124) surface (1243) of said longitudinal profile groove (122) merges with one of said opposite lateral walls wall surface portions (132, 133) (1324) of said pocket.

40. The key as defined in claim 34, wherein the a vertical dimension (h) of said ridge portion (128), measured in said plane of said lower external side wall surface (123) and the upper side wall surface (123) (1123′) of the flat one piece key blade (120), is more than half of the said smallest opening width (w) of said longitudinal profile groove (122) adjacent to said external side wall surface (123), said smallest opening width (w) being measured as a perpendicular projection onto said inner wall surface (124) of said longitudinal profile groove (122).

41. The key as defined in claim 40, wherein said vertical dimension (h) of said ridge portion (128) is equal to or greater than said smallest opening width (w).

42. The key as defined in claim 34, constituting wherein the flat one piece key blade (120) is formed from a key blank with a continuous upper edge portion configured so as to permit coded recesses to be cut therein.

43. The key as defined in claim 34, having coded recesses (102a . . . 102e) cut into said ridge portion (128), so as to form a side code on the flat one piece key blade (120), said side code recesses being configured to cooperate with at least one side tumbler (105) in an associated lock.

44. The key as defined in claim 43, wherein said side code recesses (102a . . . 102e) forming a side code constitute a wave-like, longitudinal code pattern.

45. The key as defined in claim 43, wherein said side code recesses (102a . . . 102e) are cut into the whole material thickness of said ridge portion (128), so that the side code recesses reach all the way from the outside external side wall surface (123) of said ridge portion (128) into said longitudinal pocket (135) of the undercut profile groove (122).

46. The key as defined in claim 43, wherein said side code recesses (102a . . . 102e) are cut from an upper edge of the ridge portion (128) down to various levels between said upper edge and the a lowermost part of said longitudinally extending pocket (135).

47. The key as defined in claim 43, wherein said side code recesses (102a . . . 102e) form concavities with lower bottom portions located at a number of different levels, each representing a code.

48. The key as defined in claim 46, wherein said different levels also include an uppermost level at the upper edge (102f) of said ridge portion (128).

49. The key as defined in claim 46, wherein the number of different levels is at least three.

50. The key as defined in claim 34, wherein the inner wall surface (124) of said longitudinal profile groove and the adjoining longitudinal pocket (135) are is located at a depth distance from said external side wall surface (123) of the flat one piece key blade (120) which is greater than half the thickness of said flat one piece key blade (120).

51. The key as defined in claim 34, wherein said substantially flat one piece key blade (120″) has an upper and lower portions (151″, 150″), each portion (151″) having an undercut groove (122″) with said innermost longitudinal pocket (135″) (1354), such that the key is symmetrical and can be inserted either way into an associated keyway of said cylinder lock.