DUST COVER FOR LOCK CYLINDER KEY CHANNELS

Abstract

 Dust cover for lock cylinder key channels, of the type used in locks situated in environments exposed to dust and that uses gates to seal and prevent the entry of such particles of dust or dirt via the key channel of the lock, wherein each of the dust cover gates (1) is associated with a permanent magnet (2), said gates being housed in a transverse groove (6) incorporated in the rotor (5), said groove (6) being transverse to the main axis (3a) of the lock cylinder (3) in which the dust cover gates (1) are housed face-to-face with each other and with their line of contact (1 b) centred in the key channel (8).

Description

FIELD OF THE INTENTION

[0001] This invention relates to a dust cover for lock cylinder key channels, of the type used in locks situated in environments exposed to dust and using gates to seal and prevent the entry of such particles of dust or dirt via the key channel of the lock cylinder, which are liable to cause the lock to malfunction.

STATE OF THE PRIOR ART

[0002] Currently and with reference to the state of the art, it is a common and known practice to use different dust cover devices arranged in locks used in environments that create high levels of dirt particles, such as carpentry workshops, mechanical workshops, etc., where large quantities of dust or small shavings are generated that are liable to enter via the key channel and be deposited inside the lock cylinder, causing blockage or malfunction of said cylinder.

[0003] A common solution used in the locksmith trade to solve the above-mentioned problem is based on the placement of a small swivel plate located on the front of the lock cylinder, which covers the key channel when placed on the cylinder. This solution means that the user is responsible for preventing the entry of dirt into the key channel, and must manually place said plate in the corresponding position that covers the key channel. It is therefore very probable that on numerous occasions, due to forgetfulness or carelessness on the part of the users, the key channel of the lock will be left exposed to the exterior, allowing the entry of undesirable elements.

[0004] Another type of solution is the use of devices that contain gates associated with springs, which are displaced in a transverse direction when the key is inserted into the key channel. These gates are located inside the rotor and are associated with elastic springs, which maintain said gates in permanent contact, barring the way to any dirt that might be introduced via the key channel, and allow said gates to be displaced when they are contacted by the tip of the key, which can then continue to be inserted into the lock cylinder in order to reach the pins of the same. The problem with the use of this type of solution lies in the loss of elastic properties and the permanent deformations suffered by the springs, mainly due to the fatigue accumulated during their use and to the accumulation of solid particles (dust, shavings, etc.), causing the device to malfunction with the passage of time. In addition, excessive force in these springs for closing the gates may cause said gates to rub against the blade of the key when it is inserted into the key channel, creating small metal shavings that may remain trapped in the lock and causing the problem that the gates are supposed to prevent.

DESCRIPTION OF THE INVENTION AND ADVANTAGES

[0005] In the light of this state of affairs, the present invention relates to a dust cover for lock cylinder key channels, of the type used in locks situated in environments exposed to dust particles. Each of the dust cover gates is associated with a permanent magnet, said gates being housed in a transverse groove incorporated in the rotor, said groove being transverse to the main axis of the lock cylinder in which the dust cover gates are housed face-to-face with each other and with their line of contact centred in the key channel.

[0006] Thanks to this configuration, the key channel dust cover uses the magnetism of the permanent magnets associated with the respective dust cover gates to keep the way barred to any dirt that might enter via the key channel. The attraction of the magnets maintains the dust cover gates in the closed position, with the line of contact between the two gates centred in the key channel, so that before the corresponding key is inserted, when the tip of said key encounters the dust cover gates, the latter are displaced transversally to the main axis of the lock, allowing the key to be inserted into the rotor of the lock cylinder. When the key is withdrawn, the attraction of the magnets causes the gates to return to the closed position of the key channel, preventing any possible entry of dirt into said channel.

[0007] Another feature of the invention is that the peripheral configuration of the permanent magnet is intended to be compatible with the insertion of a part of its volume into a recess provided in the dust cover gate, the remaining volume of said permanent magnet being housed in a guide channel provided in the transverse groove.

[0008] Thanks to this configuration, the permanent magnet is attached to the dust cover gate and the possible directions of displacement of said gates are limited, since the guide channel incorporated in the rotor houses the remaining volume of the permanent magnet that is not located in the recess provided in the dust cover gate, so that said permanent magnet can move only along said channel, and similarly forcing said dust cover gate to be displaced only in the transverse direction relative to the main axis of the lock cylinder, inside the transverse groove.

[0009] Another feature of the invention is that the dust cover gates have on their exterior face a separating bevel compatible with the tip of the key which facilitates the opening of said dust cover gates when said key is inserted via the key channel of the lock cylinder.

[0010] Thanks to this configuration, when the key is inserted into the lock cylinder, there is a facilitation of the opening displacement of the dust cover gates in a transverse direction relative to the main axis of the lock cylinder, since the tip of the key is compatible with this separating bevel, providing a vertical force component that causes said displacement.

DRAWINGS AND REFERENCES

[0011] In order to provide a better understanding of the nature of the invention, the attached drawings show an industrial embodiment given purely by way of non-limitative example.

Figure 1 shows a partial cutaway isometric view of the lock cylinder (3), with an enlarged detail of said partial cutaway depicting the arrangement of the dust cover gates (1) and the permanent magnets (2) and their attachment to the rotor (5).

Figure 2 shows an isometric view of the rotor (5) with the key (10) at the initial moment of contact with the dust cover gates (1), depicting the configuration of the transverse groove (6) and the guide channel (7) of the permanent magnets (2).

Figures 3a and 3b show respective isometric views of the dust cover gates (1), with Figure 3b depicting the recess (1a) for the partial housing of the permanent magnet (2) associated with said dust cover gates (1).

Figures 4a, 4b and 4c show three sequential isometric views of what occurs when the key (10) is inserted into the key channel (8), depicting the movement performed by the dust cover gates (1) from their closed position as shown in Figure 4a to the position that allows the full passage of the key (10) as shown in Figure 4c, with Figure 4b being included as an intermediate step in the insertion of the key (10).

1.-

Dust cover gates.
1a.- Recess.
1b.- Line of contact.
1c.- Separating bevel.

2.-

Permanent magnet.

3.-

Lock cylinder.
3a.- Main axis.

4.-

Stator.

5.-

Rotor.

6.-

Transverse groove.

7.-

Permanent magnet (2) guide channel.

8.-

Key channel.

9.-

Key pins.

10.-

Key.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0012] In relation to the drawings and references itemised above, the attached plans illustrate a preferred embodiment of the invention, referring to a dust cover for lock cylinder key channels in which each of the dust cover gates (1) is associated with a permanent magnet (2), said gates being housed in a transverse groove (6) incorporated in the rotor (5), said groove (6) being transverse to the main axis (3a) of the lock cylinder (3) in which the dust cover gates (1) are housed face-to-face with each other and with their line of contact (1 b) centred in the key channel (8).

[0013] Figure 1 shows a preferred embodiment of the lock cylinder (3) incorporating the dust cover gates (1) associated with permanent magnets (2), in which the transverse groove (6) is located close to the front of the rotor (5), thus protecting practically the whole of the key channel (8) from the entry of dirt. As can be seen in Figure 3b, said dust cover gates (1) incorporate recesses (1a) on their rear portion in which the permanent magnets are housed (2).

[0014] The functioning of the invention is based on the force of attraction of the permanent magnets (2). As can be seen in Figures 1 and 2, the dust cover gates (1) are housed in the transverse groove (6), and on their rear portion, housed in the recess (1), they partially incorporate said permanent magnets (2). The remaining volume of said permanent magnets (2) is contained inside the guide channel (7) cut into the transverse groove (6) of the rotor (5), so that said guide channel (7) limits the displacement of the permanent magnet (2) and consequently that of the dust cover gates (2). The force of attraction of the permanent magnets (2) locates the adjacent dust cover gates (1) with their line of contact (1 b) centred in the key channel (8). Therefore, the device is maintained at rest in the lock cylinder (3) in the described position, with the dust cover gates (1) preventing the entry of dirt, until it is actuated via the key (10).

[0015] Figures 4a, 4b and 4c show the displacement of the dust cover gates (1) when a key (10) is inserted into the lock cylinder (3). When the tip of the key (10) encounters the separating bevel (1c) located on the exterior face of the dust cover gates (1), the force applied upon insertion causes said dust cover gates (1) to separate along their line of contact (1b) and to be displaced along a direction transverse to the main axis (3a). If the insertion of the key (10) continues, the dust cover gates (1) reach the limit of displacement in the transverse groove (6), allowing the full entry of the blade of the key (10) and allowing said blade to reach the key pins (9). When the key (10) is withdrawn from the key channel (8), the attraction of the permanent magnets (2) causes the dust cover gates (1) to return to their original position, prior to the insertion of the key (10), so that the key channel (8) remains permanently close, thus preventing the entry of dirt into the lock cylinder (3).

[0016] It should be noted that this invention is applicable both to lock cylinders (3) that use keys (10) with a flat blade and those that use edge encoding.

[0017] The essential nature of the present invention is not altered by variations in materials, form, size or arrangement of the component parts, which are described non-limitatively, this being sufficient to enable a person skilled in the art to reproduce the invention.

Claims

1. Dust cover for lock cylinder key channels, of the type used in locks situated in environments exposed to dust and using gates to seal and prevent the entry of such particles of dust or dirt via the key channel of the lock, characterised in that each of the dust cover gates (1) is associated with a permanent magnet (2), said gates being housed in a transverse groove (6) incorporated in the rotor (5), said groove (6) being transverse to the main axis (3a) of the lock cylinder (3) in which the dust cover gates (1) are housed face-to-face with each other and with their line of contact (1 b) centred in the key channel (8).

2. Dust cover for lock cylinder key channels according to the preceding claim, characterised in that the peripheral configuration of the permanent magnet (2) is intended to be compatible with the insertion of a part of its volume into a recess (1a) provided in the dust cover gate (1), the remaining volume of said permanent magnet (2) being housed in a guide channel (7) provided in the transverse groove (6).

3. Dust cover for lock cylinder key channels according to the preceding claims, characterised in that the dust cover gates (1) have on their exterior face a separating bevel (1c) compatible with the tip of the key (10) which facilitates the opening of said dust cover gates (1) when said key (10) is inserted via the key channel (8) of the lock cylinder (3).

Drawing