IL110496A - Rekeyable cylinder and keys therefor - Google Patents

Description

REKEYABLE CYLINDER AND ITS KEYS JIUAN PENG LO EKEYABLE CYLINDER AND ITS KEYS The present invention relates to a cylinder and its keys and more particularly to a rekeyable cylinder and keys which a user can remove the plug and change the profile of pins in the plug.

A cylinder is a household goods used by people in their daily life. The general requirements on a cylinder are : good protection against key picking, high reliability and easy to use. However in some occasion or situation such as apartment which changes tenant frequently or the key being stolen or duplicated, there is a need to change a key without to change the cylinder. Currently, only electronic cipher code lock or digital lock has the feature allowing to change the locking code whenever needed. An ordinary mechanical cylinder does not have the feature allowing change key (i.e. key cut profile) whenever needed. When there is a need to change a key (and key cut profile), the cylinder should be removed and replaced. It is costly and not convenient.

It is accordingly an object of the present invention to provide a rekeyable cylinder and its keys which a user can remove the plug and change the profile of pins in the plug, thereby can change the key without removing or replacing the cylinder. In other words, the present invention has the feature like that of cipher code lock which can change locking code at will, thus can increase the practical value of the cylinder and allow user to save cost when to change a key is needed.

It is another object of the present invention to provide a key which includes a flat key blade and a matching rod to form a circular crosssection key blank, thus has a better protection against key picking. The matching rod can be removed and allows the flat key blade to be duplicated just like a conventional key does, thereby providing dual advantages of protection against key picking and easy key duplication.

It is yet another object of the present invention to provide a rekeyable cylinder and keys which have the features of good protection against key picking, high reliability, simple fabrication and easy to use.

In connection with the objects set forth above, the present invention contemplates to provide a cylinder including mainly a core and a plug which is housed in the core and can be slided and rotated in the core. A plurality of pin cells are disposed respectively in the core and plug. A pair of pin cells in the core and plug can be aligned at one axis. A spring, an upper pin and a lower pin have been disposed in a pair of pin cells. When the cylinder is locked before a matched key being inserted or an unmatched key is used, some of the upper pins would enter the pin cells of the plug and prevent the plug from making rotation or linear movement against the core.

The present invention further contemplates to dispose a first control pin at one end of the core and engaging with an annular groove formed around one end of the plug, thereby allowing the plug to rotate in the core but cannot make linear motion under normal circumstance. A change key cannot touch the first control pin and can only perform usual locking and unlocking function. A control key is longer than a change key and can move the first control pin out of the annular groove of the plug, thereby allowing the plug to be removed from the core and cylinder for rearranging the positions of the pins for a changing key cut profile.

Additional objects and advantages of the present invention are made apparently in the following description having reference to the accompanying drawings. The accompanying drawings are only to serve for reference and illustrative purpose, and do not intend to limit the scope of the present invention.

FIG. 1 is a breakup view of a cylinder and a key of the present invention.

FIG. 2 is a section view of a cylinder of the present invention without a key disposed inside.

FIG. 3 is a section view of a cylinder of the present invention with an unmatched key disposed inside.

FIG. 4 is a section view of a cylinder of the present invention with a matched change key disposed inside.

FIG. 5A, 5B and 5C are crosssection views of a cylinder of the present invention illustrating a change key being disposed at different angles in the cylinder.

FIG. 6 is a section view of a cylinder of the present invention with a control key disposed inside.

FIG. 7 is a section view of a core of the present invention with the plug being removed by means of a control key.

FIG. 8 is a section view of a plug of the present invention with a changed control key.

FIG. 9A is a breakup view of a change key of the present invention.

FIG. 9B is a pictorial view of a change key of the present invention.

FIG. 10 is a pictorial view of a control key of the present invention.

Referring to FIG. 1 and FIG. 2, cylinder 10 includes mainly a core 12 which has a cylindrical through cavity 14 escentrically formed inside, a hollow cylindrical plug 18 is disposed in cavity 14 and can be slided and rotated in cavity 14, and a ring shell 20 to closely hold circumferential surface 16 of core 12.

A plurality of counter' bore shape upper pin cell 22 and lower pin cell 24 are respectively disposed on core 12 and plug 18 and are perpendicular to the axis of plug 18, a pair of pin cells 22 and 24 can be aligned with each other. The number of pin cell, and the distance between them can be changed depends on requirement. An upper pin 26 which has a flat top and an indent body and a spring 28 is disposed in an upper pin cell 22, a lower pin 30 which has a flat top and an indent body and has a different length with each other is disposed in a lower pin cell 24. A pair of pins 26 and 30 can be aligned in same vertical line against the axis of the plug 18 and can be moved up or down synchronously. At one end of core 12, there is a cone shape groove 36 to contain a positioning steel ball 32 and a spring 34 therein. At a corresponding position at one end of plug 18 there is a recess 38 to hold the steel ball 32. A complete cylinder 10 includes upper pin 26 and spring 28 disposed in upper pin cell 22, lower pin 30 disposed in lower pin cell 24, positioning steel ball 32 and spring 34 disposed in groove 36 and ring shall 20 holds core 12 tightly which in turn holds a plug 18 inside.

At one end of core 12 and beside an upper pin cell 22 there is an up counter bore 40 formed and having a first control pin 42 which has a flat top and an indent body and a spring 44 disposed therein. At one end of plug 18 there is a down counter bore 45 corresponding to up counter bore 40 with a control stud 46 which has an indent body disposed therein. At the position of down counter bore 45, an annular groove 60 is formed around the circumference of plug 18.

Control stud 45 has its bottom end disposed into keyway 50, and has its top end pressing against first control pin 42 such that first control pin 42 has its bottom end engaging with annular groove 60, thereby plug 18 can make rotation with in core 12 but cannot make linear motion along axis of plug 18.

At another end of core 12 and inside of cavity 14, there is an engaging groove 62 formed in axial direction. At another and of plug 18 and under engaging groove 62, there is an engaging counter bore 47 formed therein which houses a second control pin 61 which has an indent body. Under normal circumstances, second control pin 61 drops down due to gravity and disengages with engaging groove 62. When second control pin 61 is pressed upward and engages with engaging groove 62, plug 18 would be prevented from rotation within core 12.

Referring to FIG. 2 for status before a key is disposed inside of cylinder 10, spring 28 pushes upper pin 26 and lower pin 30 downward into lower pin cell 24. Upper pin 26 is across separation line 48 between core 12 and plug 18, thereby prevent plug 18 from making rotation or linear motion within core 12. In the mean time, bottom end of lower pin 30 is disposed into keyway 50. As lower pin 30 has different length, its bottom end is at a different level in keyway 50.

Referring to FIG. 3, when an unmatched key 52 is disposed into keyway 50, key cut 54 push lower pin 30 and upper pin 26 upward synchronously.

However the unmatched key cut 54 still keep some of upper pin 26 disposed into lower pin cell 24, and some of lower pin 30 disposed into upper pin cell 22, therefore plug 18 cannot make rotation or linear motion within core 12. & Referring to FIG. 4 and 58, when a matched change O key 56 is disposed into keyway 50, key cut 58 match the length of lower pin 30 disposed in keyway 50, thereby push lower pin 30 and upper pin 26 synchronously upward such that contact line 66 between upper pin 26 and lower pin 30 coincides with separation line 48 between core 12 and plug 18. Furthermore, the matched change key 56 has a key cut 57 to match second control pin 61 and makes it free from engaging groove 62; in addition, the matched change key 56 is short and cannot reach control stud 46, and keeping first control pin 42 to remain in annular groove 60, thus preventing plug 18 from being moved out of core 12.

In the circumstance set forth above, a matched change key 56 can make plug 18 rotating inside of core 12 (referring to FIG. 5C), to release or restore the locking status of cylinder 10. When plug 18 is rotated, a click is felt when steel ball 32 falls into recess 38, thus allowing user to recognize the angle of correct position of locking of the cylinder.

Referring to FIG. 5A, a user can insert a matched change key 56 into keyway 50 in any angle, and turn key stuck in 56 until all lower pin 30--atop the matched key cut 58, and make the contact line 66 between upper pin 26 and lower pin 30 coincides with the separation line 48 between core 12 and plug 18 (referring to FIG. 5B). Continuously turning the matched change key 56 would make plug 18 and all lower pin 30 rotating against core 12 (referring to FIG. 5C), thus release the locking status of cylinder 10.

In the present invention, the key can be inserted into a round crosssection keyway in any angle, thus making key picking more difficult as there is no specific keyway direction appearing on the outside of cylinder, therefore can enhance the protection against key picking. 70 Referring to FIG. 6, 7 and 8, a control key—2-0- is longer than a change key and can remove plug 18 out of core 12. When a control key 70 is disposed in keyway 50, key cut 76 like key cut 58 in change key set forth above can make contact line 66 between lower pin 30 and upper pin 26 coincides with separation line 48 between core 12 and plug 18. Furthermore, control key 70 has a longer key blank 72 which can push control stud 46 upward and moves first control pin 42 out of annular groove 60, thereby allows plug 18 to more linearly in axial direction. In addition, key blank 72 also moves second control pin 61 upward and makes it engage with engaging groove 62 and thereby prevents plug 18 from rotating in core 12. Such that control key 70 cannot rotates plug 18 but can pull it out of core 12. (referring to FIG. 7).

Referring to FIG. 8, a changed control key 80 has a different key cut profile comparing with original control key 70 (illustrating by key cut 82 as an example). Lower pin 30 of plug 18 is also adjusted and changed to match the key cut profile of changed control key 80, thus making changed control key 80 become the new key of cylinder 10, and making old keys 56 and 70 obsolete. Changed control key 80 can be supplied by vendor or be order-made by user.

Referring to FIG. 9A and 9B, a change key 56 has a plurality of key cut 58 on a flat key blade 84 and is sandwiched in a slot opening 92 of a matching rod 86. A fixing pin 94 and holding ring 88 are used to hold key blade 84 and matching rod 86 together tightly and to form a generally circular crosssection. Matching rod 86 has a conical end 90 to facilitate its entrance into keyway 50 by pushing lower pin 30 upward easily. When there is a need to make a duplicate key, it can be done by removing holding ring 88 and fixing pin 94, and separating key blade 84 from matching rod 86, then giving key blade 84 to a conventional locksmith for duplicating a key. It is therefore has both advantages of protection against key picking and easy of duplication when needed.

Referring to FIG. 10, control key 70 is used only for removing plug 18 out of core 12. There is generally no need to make a duplicated control key. Therefore control key 70 can be made by an integrated key blank 72 with round crosssection. Key cut 96 of control key 70 match exactly key cut 58 of a change key 56. Furthermore key cut 96 has its groove formed laterally on key blank 72 and has it two side walls forming respectively a vertical surface against the axis of key blank 72 to facilitate the linear movement of plug 18 in core 12.

It is thus can be seen that the present invention allows user to remove the plug out of the cylinder, to change the arrangement and the length of lower pins, thereby to change the key cut profile of a matched key. It thus has similar func ;ion of a cipher code lock of allowing to change a cipher code. When a change key is lost or stolen, user can change a key and to adjust the plug to prevent possible key picking without the need to replace the cylinder, it is therefore greatly enhance the practical value of a cylinder and reduce the cost to a user.

Claims (2)

- 13 - 110496/3 CLAIMS :

1. A change key for a rekeyable cylinder having a flat key blade which is sandwiched m a slot opening of a matching rod to form a generally round crossection, said change key further having a holding ring to hold said key blade tightly in said matching rod, said change key having key cut profile matching a flower pin which is moved into a keyway such that resulting contact line between an upper pin and a lower pin coincides with separation line between a core and a plug, said change key cannot reach a control stud thereby to allow, said first control pin engaging with an annual groove and thus preventing a plug from making linear movement in said core .

2. A change key according to claim 1 wherein said matching rod having a conical front end. rs A-C : \UP51 H\F I LES\CL6701