GB2184155A

GB2184155A - A lock key

Info

Publication number: GB2184155A
Application number: GB08627477A
Authority: GB
Inventors: Jack William Taylor; Andrew Martin Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-11-19
Filing date: 1986-11-17
Publication date: 1987-06-17
Also published as: GB8528444D0; GB8627477D0

Abstract

A key 1 comprises an elongated shaft having two axially spaced sections 2, 3 spaced either side of a groove 4. Each section includes one or more channels 7 having surface relief features 8 provided therein so that when the key is inserted into a lock, the surface relief features move respective detainer members, e.g tumblers, to their predetermined position so that a rotatable member, e.g. barrel of a cylinder lock, can be rotated. One section of the key can rotate the rotatable member when inserted from one side of the lock and the other section can rotate the rotatable member when inserted from the other side of the lock. <IMAGE>

Description

SPECIFICATION A lock key This invention relates to a key for a lock and in psrticular to a key for operating a key mechanism having a rotatable member prevented from rotation by at least one detainer member.

A typical key mechanism consists of detainer members in the form of sliders or pins, which are and positioned radially from the centre of a rotatable plug or barrel and normally prevent rotation therof. The plug has a key hole of form corresponding to the shape of a key so that on the insertion of the correct key, the detainers are moved to a predetermined position by the key whereby the detainer members can no longer prevent rotation of the plug so that rotation of the key rotates the plug and causes movement of an operatively connected locking member.

A known example of a key comprises a cylindrical shaft with a series of countersinks on the periphery thereof, which are of predetermined depth for moving the detainer members to their predetermined positions when inserted in the key mechanism. However, it has been found that some combinations of indents reduce the diameter of the key to a point where it is difficult to ensure reliable and correct operation of the key to rotate the plug even when a key having a correct combination of indents relative to the detainer members is inserted in the keyhole. Furthermore, a key including a number of indents around the periphery thereof does not give the visual appearance of a secure and safe key mechanism which may be a deterrent to their use.

Another known example of a key comprises a cylindrical shaft with axial splines radiating from the axis of the shaft. The splines have indents in the form of notches or slots which conform in position to the detainer members of the plug when the key is inserted. It has again been found that some combinations of indents prevent correct location of the key in the keyhole of the plug with consequent unreliable ability of operation. In addition, the cutting of such notches or slots in the splines create sharp corners which can act as a deterrent to there general use.

It is therefore an object of the present invention to provide a key for use in locks with the key mechanisms described above but which can include indents or notches for cooperation with the detainer members in the key mechanism without affecting the outside liameter of the key and consequent location in the keyhole. It is important that this object is achieved without reduction in the number of different combinations for the keys and without creating objectionaly sharp corners.

According to the invention there is provided a key for insertion into a lock having a rotatable member prevented from rotation by the action of at least one detainer member unless the detainer members are moved to respective predetermined positions, the key comprising an elongate shaft having one or more substantislly parallel aligned channels provided in the outer surface of the shaft, the or each channel having located therein detainer operating means for moving respective detainer members to their predetermined positions when the key is located into the lock. In this way, the outer surface of the shaft of the key is still defined by the circumference of the key between the channels.Consequently, a full diameter of key is provided so that when it is inserted in the key mechanism, it has a good location or bearing on the plug of the mechanism to ensure reliable and correct operation, In addition, objectionably sharp corners are not produced.

Conveniently, the channels are spaced axially aligned around the shaft axis. In this way, a suitably large number of combinations for the key mechanism can be provided.

In a prefered embodiment of the invention, a single detainer operating means is located in each channel and can comprise an indentation located on the base of the channel to act on, in use, the associated detainer member to move it to its predetermined position. Alternatively, the detainer operating means can comprise an elevation located on the base of the channel to act on, in use, the associated detainer member to move it to its predetermined position. Consequently, when the key is inserted, the detainer members are moved to their respective predetermined positions as a result of encountering either indentations or elevations located in the aformentioned channels. The width of each channel can be determined by the need to leave a solid portion between each channel to provide a fuller outer surface.The depth of each channel can be variable along the shaft length, in particular at the positions for cooperation with the detainer members when the key is inserted in the key mechanism. In effect, the depth of each channel at these positions determines the amount of movement imparted to each respective detainer member to enable the key to rotate.

Conveniently, the sides defining the channels can be parallel or alternatively tapered towards the said axis. Consequently, they are of greater width at the top of the channel than at the bottom of the channel to thus facilitate entry of the key into the key mechanism and to avoid contact between the respective detainers and the wall of the channels in the key.

Conveniently, the shaft has two axially spaced sections, each section including one or more channels with detainer operating means so that one section can rotate the rotatable member when inserted from one side of the lock and the other section can rotate the rota table member when inserted from the other side of the lock. In a prefered embodiment of the invention, each section includes five circumferentially spaced channels, each channel including two detainer operating means.

An example of the present invention will now be described with reference to the accompany drawings in which: Figure 1Illustrates schematically a key embodying the present invention.

Figure 2-Illustrates a top view of the shaft of the key shown in figure 1.

Figure 3-Illustrates a cross sectional view along the lines x-x shown in figure 2.

Refering to the drawings, a key 1 comprises an elongate shaft split into an end section 2 and an intermediate section 3. The sections 2 and 3 are axially spaced either side of a groove 4 recessed into the shaft. One end of the shaft includes a handle or bow 5 whereas the other end 6 of the shaft is tapered to a point to facilitate entry of the key into the keyhole of a key mechanism.

Refering now to figures 2 and 3, the section 3 has located around the circumference of the shaft five channels 7, as shown in figure 3.

Figure 2 illustrates only one of the channels for the purposes of clarity. Each channel 7 comprises a recessed groove formed in the outer circumference of the shaft of the key.

Each channel is formed to have 2 spaced steps 8 which are elevated relative to the base of the channel 7 but are not sufficiently elevated to extend beyond the circumference of the section 3. Identical sets of channel 7 and steps 8 are formed in both section 2 and 3.

The channels 7 and the associated steps 8 are formed in a position so that when the key illustrated is inserted into a key mechanism the steps 8 act on and move detainer mem bers of the key mechanism so that those detainer members are moved to a predetermined position whereby with the rotation of the key, a rotatable plug in the key mechanism, which is operatively connected to a lock, can rotate to effect locking or unlocking. It will be appre ciated from the figures that the means operat ing the detainer members are recessed relative to the circumference of the shaft of the key and that the general circumference of the shaft is maintained by ensuring that the chan nel 7 are narrow relative to the width of the shaft between those channels.

It will be apparent from figures 1 and 2, that location of the key when entered in a key mechanism is effected by a projection 9 pro vided on the key in abutment with a face of the key mechanism. The groove 4 is provided forwardly adjacent the abutment projection and of a width to accommodate the thickness of the abutment face of the plug, key mecha nism or casing in which the key mechanism is located. Rotation of the plug in the key mechanism is effected by a form, such as a flat face, in the keyhole in co-operation with a corresponding surface 10 on the key, the flat form of the key extending each side of the circumferential groove 4.

It will be apparent that the channels may be tapered towards the axis of the shaft so that they are of greater width away from the axis than closer to the axis. This facilitates entry of the key into the key mechanism and avoids contact between the detainer members and the wall of the channels 7. Furthermore, although steps 8 are illustrated, it will be apparent that indentations may replace- the steps and the depth of each channel can be variable along its length to produce steps and or indentations.

As illustrated, the channels 7 extend either side of the groove 4 so that when the key is entered in the key mechanism from one side, the steps positioned between the end of the key 6 and the groove 4 cooperate with the detainer members in the plug for rotation thereof while the steps positioned between the groove 4 and the bow or handle 5 rotate outside the key mechanism. When the key is entered from the other side of key mechanism, the steps between the bow 5 of the key and the groove 4 cooperate with the detainer members in the plug for rotation thereof while the steps positioned between the end of the key 6 and the groove 4 rotate outside the key mechanism.

It will be apparent that the provision of a double set of channels either side of the groove 4 is unnecessary for key operation from one side only, such as safe door locks, padlocks etc. Abutment faces to assure alignment of the steps 8 in the channels of the key with the detainer members and to withdraw the key from the mechanism are necessary. If for some reason the end of the key is required to pass through, and protrude from the key mechanism, the channels 7 may be incorporated only in the shaft between the groove 4 and the bow 5.

Preferably, the steps 8 are formed to taper to meet the base of the channel 7 at the end facing the key point 6. This facilities initial lifting of the detainer members while the key is being inserted into the key mechanism.

Although the key illustrated has a cylindrical shaft, it should be noted that other shape shafts can be provided having the channels 7 therein. Furthermore, although the key de scribed is a single unit, the present invention encompasses a key having the shaft deta chably connected to the bow. Finally, it will be apparent that different numbers of steps 8 or indentations and channels 7 can be pro vided as required for each particular key mechanism.

Claims

1. A key for insertion into a lock having a rotable member prevented from rotation by the action of at least one detainer member unless the detainer members are moved to respective predetermined positions, the key comprising an elongate shaft having one or more substantially parallel aligned channels providing in the outer surface of the shaft, the or each channel having located therein detainer operating means for moving respective detainer members to their predetermined positions when the key is located into the lock.

2. A key as claimed in claim 1 wherein the channels are parallel to the axis of said shaft.

3. A key as claimed in claim 2 wherin the channels are provided at equally spaced intervals around the shaft axis.

4. A key as claimed in any preceding claim wherein a single detainer operating means is located in each channel.

5. A key as claimed in any preceding claim wherein the detainer operating means comprises a surface relief feature located on the base of the channel to act on, in use, the associated detainer member to move it to its predetermined position.

6. A key as claimed in any preceding claim wherein the shaft has two axially spaced sections, each section including one or more channels with detainer operating means so that one section can rotate the rotatable member when inserted from one side of the lock and the other section can rotate the rotable member when inserted from the other side of the lock.

7. A key as claimed in any preceding claim wherein the channels have a narrowing taper towards the shaft axis.

8. A key for insertion into a lock having a rotatable member preventing from rotation by the action of at least one detainer member unless the detainer members are moved to respective predetermined positions, substantially as herein described with reference to the accompaning drawings.