GB2107380A - Cylinder lock - Google Patents

Abstract

A disc-tumble cylinder lock having a keyway (2) features a key (1) having off-set side faces of the key coded (12, 14, 16 and 13, 15, 17 respectively) to engage disc tumblers (4). <IMAGE>

Description

SPECIFICATION Improvements relating to locking devices This invention relates to a disc tumbler Barrel type Locking Device. The device having a key that when entered into the barrel each disc tumbler (having a predetermined position on the key) will be driven by ramp on the key; the disc tumbler (in future to be called the tumbler) will be displaced to line up with the circumference of the barrel so that the key is then able to rotate barrel to the required rotational degree, if correct key. If not the correct key, tumblers to be displaced to form an abutment preventing rotation.

Disc tumbler locking devices as known to date are easily picked by rippling. The main reason is that the key-way is normally of a large aperture, so that a rippler (a wave form top and bottom edge) can be of strength to ripple and rotate barrel. Also tumbler reaction faces being in line (one above and one below) is an aid to rippling.

When a large number of keys each differing is required more tumblers are necessary thereby requiring a longer key and barrel. The reason being the conventional key has only two faces (top and bottom) to differ with (key cuts) as the "two side faces" have to be used to support the key i.e. fluting to form a ledge on the key and bullets in the barrel.

To form thefluting (ledge) a large proportion of material is machined away leaving a thin portion to cut steps for differing. Therefore the appearance or form and action is like a saw causing a short life of tumbler through wear.

The following description of proposed improvements has tumblers that react to the side faces of the key leaving upper and lower faces for key support in barrel (no bullets required). By using the side faces and tumbler reaction face being off-set it will be seen that there are four areas not two areas as per conventional key useable for differing. The advantage becomes apparent that the key is reduced, the barrel shorter, and production costs lower, also a higher class of security than the present system.

The method of cutting key gives a greater area for key reaction thereby considerably increasing tumbler life against wear.

It will be readily seen that the invention doubles the working area of the conventional key and also reduces the buildup of manufacturing tolerances.

Now to describe the invention by way of example with reference to the accompanying drawing wherein Figure 1 shows a section through a disc tumbler locking barrel pocket with the tumbler shaded also tumbler drive spring and pocket.

Figure 2 shows a view of key face (side face).

Figures shows a view of key lower face with differing steps displayed.

Figure 4 shows an end view of key (double entry).

The disc tumbler device shown in the accompanying drawing is intended for incorporation in any locking device assembly. The key as shown in the accompanying drawing is intended for incorporation in any locking device tumbler disc or pin. The method of machining i.e. a cutter coming in from the side (whether round or side and face cutter) to depth required. When key form 1 of Figure 4 enters key-way 2 (shaded) of barrel Figure 1 causing tumbler 4 of Figure 1 to move out of spline 5 of lock housing 6 (chain dotted) of Figure 1 and if correct key, with key stop face 23 Figure 2 against stop face of barrel, projection face 10 of tumbler 4 will line up with circumferential face 18 of barrel 3 Figure 1 and face 7 of tumbler 4 Figure 1 and seating on key step face 8 of Figure 3.When key is removed and rotated through 180 and then re-entered, key differ face 9 of Figure 3 is used to align tumbler 4 Figure 1 (double entry) for single entry. Both sides of key would be differed or cut as shown (Figure 2): three steps on face 19 of key, i.e. 12, 14and 16, and key steps 13, 15 and 17 on side face 20. As will be seen, these positions may be reversed using key side faces 21 and 22. When an incorrect key is applied projection face 10 will move below circumferential face 18 of barrel 4 and projection face 11 will enter spline 12 of housing 6 and prevent rotation of barrel 4.

The aforegoing description is for every tumbler used. Figure 4 illustrates double entry key for a barrel having six tumblers. Position No. 12 is the position of No. 1 tumbler, position No. 13 is the position of No. 2 tumbler, position No. 14 is the position of No. 3 tumbler, position No. 15 is the position of No. 4 tumbler, position No. 16 is the position of No. 5 tumbler and position No. 17 is the position of No. 6tumbler.

Duplication of steps on key for double entry is indicated by letter lower case (a) affix.

1. A disc tumbler device having off-set side face of key actuating on an off-set face of tumbler. The off-set condition enabling key entry differing without bullets or wards.

2. As in claim 1 the off-set condition with tumblers spaced with every other tumbler opposite making it difficult to pick (or ripple) requiring two straight separate ripplers causing difficulty of turning barrel whilst rippling or a very special rippler by an expert.

3. As in claim 1 a key that has two or more positions on each side face for lateral differing over keylength.

4. As in claim 1 method of differing or cutting of key giving a greater surface area for tumbler activating thereby increasing life of tumbler against wear.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to locking devices This invention relates to a disc tumbler Barrel type Locking Device. The device having a key that when entered into the barrel each disc tumbler (having a predetermined position on the key) will be driven by ramp on the key; the disc tumbler (in future to be called the tumbler) will be displaced to line up with the circumference of the barrel so that the key is then able to rotate barrel to the required rotational degree, if correct key. If not the correct key, tumblers to be displaced to form an abutment preventing rotation. Disc tumbler locking devices as known to date are easily picked by rippling. The main reason is that the key-way is normally of a large aperture, so that a rippler (a wave form top and bottom edge) can be of strength to ripple and rotate barrel. Also tumbler reaction faces being in line (one above and one below) is an aid to rippling. When a large number of keys each differing is required more tumblers are necessary thereby requiring a longer key and barrel. The reason being the conventional key has only two faces (top and bottom) to differ with (key cuts) as the "two side faces" have to be used to support the key i.e. fluting to form a ledge on the key and bullets in the barrel. To form thefluting (ledge) a large proportion of material is machined away leaving a thin portion to cut steps for differing. Therefore the appearance or form and action is like a saw causing a short life of tumbler through wear. The following description of proposed improvements has tumblers that react to the side faces of the key leaving upper and lower faces for key support in barrel (no bullets required). By using the side faces and tumbler reaction face being off-set it will be seen that there are four areas not two areas as per conventional key useable for differing. The advantage becomes apparent that the key is reduced, the barrel shorter, and production costs lower, also a higher class of security than the present system. The method of cutting key gives a greater area for key reaction thereby considerably increasing tumbler life against wear. It will be readily seen that the invention doubles the working area of the conventional key and also reduces the buildup of manufacturing tolerances. Now to describe the invention by way of example with reference to the accompanying drawing wherein Figure 1 shows a section through a disc tumbler locking barrel pocket with the tumbler shaded also tumbler drive spring and pocket. Figure 2 shows a view of key face (side face). Figures shows a view of key lower face with differing steps displayed. Figure 4 shows an end view of key (double entry). The disc tumbler device shown in the accompanying drawing is intended for incorporation in any locking device assembly. The key as shown in the accompanying drawing is intended for incorporation in any locking device tumbler disc or pin. The method of machining i.e. a cutter coming in from the side (whether round or side and face cutter) to depth required. When key form 1 of Figure 4 enters key-way 2 (shaded) of barrel Figure 1 causing tumbler 4 of Figure 1 to move out of spline 5 of lock housing 6 (chain dotted) of Figure 1 and if correct key, with key stop face 23 Figure 2 against stop face of barrel, projection face 10 of tumbler 4 will line up with circumferential face 18 of barrel 3 Figure 1 and face 7 of tumbler 4 Figure 1 and seating on key step face 8 of Figure 3.When key is removed and rotated through 180 and then re-entered, key differ face 9 of Figure 3 is used to align tumbler 4 Figure 1 (double entry) for single entry. Both sides of key would be differed or cut as shown (Figure 2): three steps on face 19 of key, i.e. 12, 14and 16, and key steps 13, 15 and 17 on side face 20. As will be seen, these positions may be reversed using key side faces 21 and 22. When an incorrect key is applied projection face 10 will move below circumferential face 18 of barrel 4 and projection face 11 will enter spline 12 of housing 6 and prevent rotation of barrel 4. The aforegoing description is for every tumbler used. Figure 4 illustrates double entry key for a barrel having six tumblers. Position No. 12 is the position of No. 1 tumbler, position No. 13 is the position of No. 2 tumbler, position No. 14 is the position of No. 3 tumbler, position No. 15 is the position of No. 4 tumbler, position No. 16 is the position of No. 5 tumbler and position No. 17 is the position of No. 6tumbler. Duplication of steps on key for double entry is indicated by letter lower case (a) affix. CLAIMS

1. A disc tumbler device having off-set side face of key actuating on an off-set face of tumbler. The off-set condition enabling key entry differing without bullets or wards.

2. As in claim 1 the off-set condition with tumblers spaced with every other tumbler opposite making it difficult to pick (or ripple) requiring two straight separate ripplers causing difficulty of turning barrel whilst rippling or a very special rippler by an expert.

3. As in claim 1 a key that has two or more positions on each side face for lateral differing over keylength.

4. As in claim 1 method of differing or cutting of key giving a greater surface area for tumbler activating thereby increasing life of tumbler against wear.