The present invention relates to a lock cylinder. More particularly, the present invention relates to a lock cylinder that includes a housing and a plug.
Generally, lock cylinders include a housing and a plug that define respective pin chambers to receive pin pairs. The pin pairs include outer pins substantially disposed within the housing, and inner pins disposed within the plug. Springs are often used to bias the pin pairs toward a key slot in the plug. More specifically, the springs are engaged with the outer pins, which in turn engage the inner pins and force the inner pins into the key slot. In the absence of a correct or appropriate key, the outer pins are partially disposed in the plug and block rotation of the plug within the housing.
The plug is rotatable relative to the housing in most conventional lock cylinders. A shear line is defined where the plug and the housing come together. When an appropriate key is inserted into the key slot, the inner and outer pins are moved. The junctions of the inner pins and the outer pins are aligned with the shear line, which allows the plug to be turned to a locked or unlocked position. In other words, the appropriate key will move the inner and outer pins such that the outer pins are disposed completely in the housing, and the inner pins are disposed completely in the plug.
In one embodiment, the invention provides a lock cylinder that includes a housing and a plug. The housing defines a cylindrical cavity and an outer pin chamber that is adapted to house an outer pin. The plug is disposed in the cavity and is rotatable between a locked position and an unlocked position, and includes an inner pin chamber that is aligned with the outer pin chamber when the plug is in the locked position. A key slot is disposed at least partially through the plug, and is in communication with the inner pin chamber. The lock cylinder further includes an inner pin positioned in the inner pin chamber for movement along an axis and engageable with a key inserted into the key slot. The inner pin is also engageable with the outer pin when the plug is in the locked position, and includes an outer surface that defines a non-axial groove. The lock cylinder also includes an engagement member that is supported by the plug and that extends into the groove.
In another embodiment, the invention provides a lock cylinder that includes a housing and a plug. The housing defines a cylindrical cavity and an outer pin chamber that is adapted to house an outer pin. The plug is rotatably disposed in the cavity, and includes an inner pin chamber selectively aligned with the outer pin chamber. A key slot is disposed at least partially through the plug. The lock cylinder also includes an inner pin disposed within the inner pin chamber, and an engagement member disposed within the plug and engaged with the inner pin to allow relatively slow movement of the inner pin, and to resist relatively quick movement of the inner pin.
In yet another embodiment, the invention provides a method of operating a lock cylinder. The method includes providing a housing that defines a cylindrical cavity and includes an outer pin, and providing a plug that is rotatable within the cavity and includes a key slot and an inner pin selectively aligned with the outer pin. The method further includes engaging an engagement member with the inner pin without engagement of the engagement member with the outer pin, allowing relatively slow movement of the inner pin, and resisting relatively quick movement of the inner pin.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
The housing 15 is typically fixed relative to the door, and includes a wall 35 and a pin portion 40. As shown in
The housing 15 is typically fixed relative to the door, and the plug 20 is movable or rotatable relative to the housing 15 between a locked position (
The plug 20 includes a first or outer end 55, a second or inner end 57 opposite the first end 55, a generally cylindrical outer surface 60, and a key slot 65. The first end 55 is accessible from the front of the lock cylinder 10, and the second end 57 is accessible from the rear of the lock cylinder 10. The key slot 65 extends longitudinally through the plug 20 from the first end 55 toward the second end 57. The key 25 is insertable into the key slot 65 at the first end 55.
The plug 20 also includes second or inner pin chambers 70 that extend substantially transverse to the key slot 65 from the outer surface 60. Each inner pin chamber 70 has an axis 75 (
In the construction of the lock cylinder 10 illustrated in
The lock cylinder 10 also includes one or more engagement members 140 housed in respective passageways 130.
As shown in
The lock cylinder 10 is assembled by inserting the plug 20 into the housing 15 after the inner pins 90 and the engagement members 140 have been positioned in the plug 20. The plug 20 is assembled by inserting the engagement members 140 into the passageways 130, and then inserting the inner pins 90 into the inner pin chambers 70. Each inner pin 90 is aligned within the inner pin chamber 70 such that the engagement portion 150 of the respective engagement member 140 is disposed within the groove 110 and engageable with the curved surface 115. The outer pins 80 are positioned in the outer pin chambers 45 after the plug 20 has been assembled and inserted into the housing 15. In embodiments that include the springs 85, the springs 85 are inserted into the pin portion 40 after insertion of the outer pins 80. The removable member 50 is positioned over the outer pin chambers 45 after insertion of the outer pins 80.
In operation, the springs 85 bias the outer pins 80 and the inner pins 90 inward such that the outer pins 80 partially extend into the inner pin chambers 70 without a proper or appropriate key 25 in the key slot 65. The inner pins 90 are in communication with the key slot 65 for selective engagement by a key 25 inserted into the key slot 65. The engagement members 140 are not directly engaged by the key 25 when the key 25 is inserted into the key slot 65. In embodiments that do not include the springs 85, the outer pins 80 move inward under the force of gravity.
The engagement members 140 extend into the non-axial grooves 110 to selectively allow movement of the inner pins 90 toward the outer pins 80. More specifically, each engagement member 140 and corresponding non-axial groove 110 cooperate to allow relatively slow movement of the corresponding inner pin 90, and cooperate to resist relatively quick movement of the inner pin 90.
Relatively slow movement of the inner pins 90 is generally defined as deliberate or uniform movement that can be facilitated by insertion of an appropriate key 25 into the key slot 65. When the appropriate key 25 is inserted into the plug 20, the pin engaging portions 30 are engaged with the end 100 of each inner pin 90. The inner pins 90 are slowly moved outward generally along the axis 75 by the key 25, and engage and move the outer pins 80. As each inner pin 90 is moved upward by the key 25, the engagement member 140 causes a respective inner pin 90 to rotate. Each inner pin 90 rotates due to the respective semispherical end portion 155 following the path defined by the non-axial groove 110. Each inner pin 90 rotates about the axis 75 in response to movement of the inner pin 90 outward along the axis 75 due to the engagement member 140 extending into the non-axial groove 110. The shape of the non-axial groove 110 generally defines the rotation of the inner pin 90. The inner pins 90 engage the outer pins 80 to align the parting lines 95 with the shear line 42 such that the plug 20 can be rotated to the unlocked position.
Relatively quick movement of the inner pins 90 is generally defined by an atypical jamming or bumping movement that attempts to move the outer pins 80 out of the inner pin chambers 70 in an attempt to rotate the plug 20 to the unlocked position without using an appropriate key 25. In a conventional lock, relatively quick movement of the inner pins 90 could be caused by bumping the inner pins with an improper or inappropriate key (not shown) in an attempt to pick the lock. In the lock cylinder 10, the spherical end portions 155 of the locking members 140 limit or resist movement of the inner pins 90 along the axis 75 when the inner pins 90 are bumped. The end portion 155 engages the sidewalls of the curved surface 115 due to the force exerted on the inner pin 90, causing friction or resistance between the curved surface 115 and the end portion 155. The friction or resistance caused by bumping the inner pin 90 substantially limits linear and rotational movement of the inner pin 90, and inhibits outward movement of the inner pin 90 toward the outer pin 80. As a result, relatively quick movement of the inner pin 90 is inhibited, the outer pin 80 remains partially disposed in the inner pin chamber 70, and the plug 20 cannot be rotated to the unlocked position.
The lock cylinder 10 described above and illustrated in
In addition, the materials discussed above with regard to the inner pins 90 and the engagement members 140 are only exemplary, and shall not be limited. One of ordinary skill in the art will recognize and understand that many variations of the material for the inner pins 90 and the material for the engagement members 140 are possible. In addition, one of ordinary skill in the art will appreciate that some materials can interact with other materials in different ways, such as increasing or decreasing friction between the inner pins 90 and the engagement members 140.
The material of the engagement members 140 interacts with the material of the inner pins 90 to define a coefficient of friction between the materials of the end portions 155 and the curved surfaces 115. The coefficient of friction is indicative of the amount of resistance between the materials of the respective end portions 155 and the curved surfaces 115. A higher coefficient of friction between the materials defining the end portion 155 and the curved surface 115 results in a larger resistance by the inner pin 90 to movement in the outward direction toward the outer pin 80. A lower coefficient of friction between the materials of the end portion 155 and the curved surface 115 results in smaller resistance by the inner pin 90 to movement in the outward direction toward the outer pin 80.
As one of ordinary skill in the art will appreciate and understand, the scope of the present invention considers that operation of the lock cylinder 10 as described above is dependent on, among other things, various features or characteristics of the inner pins 90 and the engagement members 140. These characteristics include, but are not limited to, the size and shape of the engagement members 140 relative to the size and shape of the non-axial grooves 110, and the material selected for the inner pins 90 and the material selected for the engagement members 140.
Various features and advantages of the invention are set forth in the following claims.