FIELD OF INVENTION

The present invention relates to means for preventing unintended rotation of key in cylindrical locks of automobiles. More particularly  the said means preventing the loss of functionality of cylinder lock for vehicles during unintended use. More particularly  the said invention relates to preventing the rotation of key by the user at unintended position. Intended use here refers to rotation of key from ‘OFF’ to ‘ON’ position & vice versa  rotation of key from ‘LOCK’ to ‘OFF’ position in key pushed condition & vice versa. Unintended use here refers to rotation of key from ‘OFF’ position to ‘ON’ position in key pushed condition.

BACKGROUND AND PRIOR ART

It is known that in cylinder locks there is a rotating part  commonly known as cylinder & fixed part  commonly known as stator. Stator is rigidly fixed on the vehicle & cylinder is rotated by the use of key. The rotation of the cylinder should be possible only at the intended positions to meet the functionality of the cylinder lock. Presently in cylinder locks there are different means to stop the rotation of the key at unintended positions. This is done by restricting the movement of cylinder by means of stopper arrangements which are provided in the Stator & the Cylinder of the Cylinder lock .But using such mechanisms has a limitation that it increases the packaging dimensions especially the height of the cylinder lock (distance (h) specified in figure 3). So in cylinder locks where packaging dimensions cannot be increased beyond certain limit such mechanisms cannot be used.
Further  it has been observed that if there is no stopper means to restrict the rotation of key at unintended position (rotation of key in pushed condition from OFF to ON) than there are chances that cylinder lock may become non-operational. At unintended position rotation of key will result in movement of bracket latch bearing in backward direction that is inside the lock which in turn will move the lock bar in backward direction ( as lock bar & bracket latch bearing are connected). Backward movement of lockbar beyond certain limit will result in lockbar loosing support in body thereby resulting in falling of lockbar inside the cylinder lock & hence it will become non-operational. Therefore  the inventors of the present invention felt a grave need to overcome the above mentioned drawback  and therefore  there is need to redesign the mechanism to prevent the unintended key rotation especially from ‘OFF’ to ‘ON’ position in key pushed condition.

OBJECTIVES OF THE INVENTION

The primary objective of the present invention is to provide means for preventing unintended rotation of key in cylindrical locks of automobiles.
Another objective of the present invention is to provide a mechanism that prevents the unintended rotation of key in a cylinder lock without increasing the packaging dimensions of cylindrical lock.

BRIEF DESCRIPTION OF FIGURES

Further aspects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying drawings. Reference numerals have been used to refer to identical or similar functionally similar elements. The figures together with a detailed description below  are incorporated in and form part of the specification  and serve to further illustrate the aspects and explain various principles and advantages  in accordance with the present invention wherein:

Figure 1 shows the exploded view of cylinder lock.
Figure 2 shows the sectional view of cylinder lock.
Figure 3 shows the different types of stopper mechanism
Figure 4 shows the inside view of cylinder lock
Figure 5 shows Intended use of lock.
Figure 6 shows unintended use of lock.
Figures 7 and 8 shows the intended and unintended operation.
Figure 9 shows the unintended operation wherein inward movement of latch bar and falling of lock bar is demonstrated.

Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example  the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of aspects of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

While the invention is susceptible to various modifications and alternative forms  specific aspect thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood  however that it is not intended to limit the invention to the particular forms disclosed  but on the contrary  the invention is to cover all modifications  equivalents  and alternative falling within the spirit and the scope of the invention as defined by the appended claims.
The Applicants would like to mention that the drawings are drawn to show only those specific details that are pertinent to understanding the aspects of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

The terms “comprises”  “comprising”  or any other variations thereof  are intended to cover a non-exclusive inclusion  such that a setup  device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words  one or more elements in a system or apparatus proceeded by “comprises… a” does not  without more constraints  preclude the existence of other elements or additional elements in the system or apparatus.

In the following detailed description of the aspects of the invention  reference is made to the accompanying drawings that form part hereof and in which are shown by way of illustration specific aspects in which the invention may be practiced. The aspects are described in sufficient details to enable those skilled in the art to practice the invention  and it is to be understood that other aspects may be utilized and that charges may be made without departing from the scope of the present invention. The following description is  therefore  not to be taken in a limiting sense  and the scope of the present invention is defined only be the appended claims.

Accordingly  the present invention relates to providing means for preventing the rotation of key (3) at unintended Position without increasing the packaging dimensions of the cylindrical lock. The means can be a cylinder (11.1) in the body switch (1)  rib (11.2) in body switch (1) or a Stopper (11.3) in body (4). The present invention involves providing rib (11.2) in body switch (1) at a particular position so that the movement of bracket latch bearing (2) is restricted if user tries to rotate the key (3) from ‘OFF’ to ‘ON’ Position in pushed condition (unintended use) resulting in prevention of key rotation.

INTENDED USE:

Key (3) insertion by user at OFF position. Rotating the key (3) in clockwise direction to ON Position. Here no movement of bracket latch bearing (2) takes place as Cam (5) is not in contact with bracket latch bearing (2). Rotating the key (3) in anticlockwise direction to OFF position. Here also no movement of bracket latch bearing (2) takes place as cam (5) is not in contact with bracket latch bearing (2).
Pushing & Rotating the Key (3) in anticlockwise direction to Lock Position. Here movement of bracket latch bearing (2) takes place in forward direction as Cam (5) comes in contact with bracket latch bearing (2).
Pushing & rotating the Key (3) in clockwise direction to OFF position. Here movement of bracket latch bearing (2) takes place in backward direction as Cam (5) comes in contact with bracket latch bearing (2) and in last Key withdrawal at OFF position

UNNTENDED USE: (rotation of key from ‘OFF’ position to ‘ON’ position in key pushed condition)
Key (3) insertion by user at OFF position.
Pushing & Rotating the key (3) in clockwise direction to ON Position. Here movement of bracket latch bearing (2) takes place as Cam (5) comes in contact with bracket latch bearing (2). It has been observed that if there is no stopper means to restrict the rotation of key at unintended position (rotation of key in pushed condition from OFF to ON) than there are chances that cylinder lock may become non-operational. At unintended position rotation of key will result in movement of bracket latch bearing in backward direction that is inside the lock which in turn will move the lock bar in backward direction as shown in figure 9 ( as lock bar & bracket latch bearing are connected). Backward movement of lockbar beyond certain limit will result in lockbar loosing support in body thereby resulting in falling of lockbar inside the cylinder lock & hence it will become non-operational.

Rotating the key (3) in anticlockwise direction to OFF position. Here also no movement of bracket latch bearing (2) takes place as cam (5) is not in contact with bracket latch bearing (2).
Pushing & Rotating the Key (3) in anticlockwise direction to Lock Position. Here movement of bracket latch bearing (2) takes place in forward direction as Cam (5) comes in contact with bracket latch bearing (2).
Pushing & rotating the Key (3) in clockwise direction to OFF position. Here movement of bracket latch bearing (2) takes place in backward direction as Cam (5) comes in contact with bracket latch bearing (2)
Key (3) withdrawal by user at OFF position.

Therefore  the present invention proposes a solution by providing means for preventing the rotation of key (3) at unintended Position without increasing the packaging dimensions of the cylindrical lock. The means can be a cylindrical pin (11.1) in the body switch (1)  rib (11.2) in body switch (1) or a Stopper (11.3) in body (4). The present invention involves providing rib (11.2) in body switch (1) at a particular position so that the movement of bracket latch bearing (2) is restricted if user tries to rotate the key (3) from ‘OFF’ to ‘ON’ Position in pushed condition (unintended use) resulting in prevention of key rotation.

ADVANTGES OF THE INVENTION

The primary advantage of the present invention is to provide means for preventing unintended rotation of key in cylindrical locks of automobiles.
Another advantage of the present invention is to provide a mechanism that prevents the unintended rotation of key in a cylinder lock without increasing the packaging dimensions of cylindrical lock.
The inventors have been working to develop the invention  so that advantage can be achieved in an economical  practical  and facile manner. While preferred aspects and example configurations have been shown and described  it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred nature of the invention  and should not be interpreted as limitations on the scope of the invention.