Patent Application
20050179556
1. Field of the Invention
The invention relates to an alarm device, more particularly to an alarm device adapted for pickproofing a lock member.
2. Description of the Related Art
Various types of conventional locks are available to meet different requirements. For instance, a lock with a keyhole is designed for operation using a key, whereas a lock with a keypad is designed for operation by keying in a correct password. For added convenience, some locks employ more than one control mechanism. For example, vehicles, such as cars, motorcycles, etc., are generally equipped with a lock that can be manually operated with the use of a key, and that can be remotely operated with the use of a remote controller. In addition, the locks on doors of some premises can be controlled using either a key or electronic sensing equipment. Locks that can be operated through remote control or through electronic sensing equipment are also equipped with a key-operated mechanism so as to permit manual locking and unlocking operations in the event of failure of the remote controlled mechanism or electronic sensing mechanism.
Conventional key-operated lock mechanisms are disadvantageous in that a keyhole in the same is designed to be easily accessible and is thus susceptible to being picked by thieves. There is thus a need to enhance security of electronic locks that incorporate key-operated mechanisms.
Therefore, the object of the present invention is to provide an alarm device for a lock member so as to overcome the aforesaid drawbacks associated with the prior art.
Accordingly, the alarm device of this invention is adapted for pickproofing a lock member that has one end formed with a keyhole. The alarm device comprises a mounting member, an alarm actuator, and an alarm generator. The mounting member includes a base plate formed with a through hole, and is adapted to be disposed adjacent to the lock member such that the through hole in the base plate is registered with the keyhole in the lock member. The mounting member is further formed with a containing space that opens toward the lock member. The alarm actuator is mounted removably in the through hole in the base plate. The alarm generator includes an alarm circuit disposed in the containing space, and a contact member connected electrically to the alarm circuit and disposed to contact the alarm actuator when the alarm actuator is mounted in the through hole in the base plate. The alarm circuit is operable in a selected one of an armed mode, where the alarm circuit generates an alarm output in response to detection by the contact member of removal of the alarm actuator from the through hole in the base plate, and a disarmed mode, where the alarm circuit is inhibited from generating the alarm output when the contact member detects the removal of the alarm actuator from the through hole in the base plate.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
The mounting member 1 is to be mounted fixedly on the door panel 10, and includes a base plate 11 and a peripheral wall 12 that extends transversely from a periphery of the base plate 11 toward the door panel 10. The base plate 11 is formed with a through hole 112. The mounting member 1 is adapted to be disposed adjacent to the lock member 2 such that the through hole 112 in the base plate 11 is registered with the keyhole 21 in the lock member 2. The base plate 11 and the peripheral wall 12 cooperate to form the mounting member 1 with a containing space 13 that opens toward the lock member 2. In this embodiment, the base plate 11 is formed with a mounting tube 111 that defines the through hole 112 and that extends in a direction away from the lock member 2. The mounting tube 111 is formed with a radial inward flange 113 that extends into the through hole 112. The radial inward flange 113 has opposite outer and inner flange surfaces to be disposed distal from and proximate to the lock member 2, respectively.
Referring to
The base seat 41 has a face plate 411 and a retaining wall 412. The face plate 411 has a rim 416 that is disposed to abut against the outer flange surface of the radial inward flange 113 when the base seat 41 is inserted into the mounting tube 111, as best shown in
Each of the retaining members 43 is received in a corresponding one of the retaining holes 417, and has opposite first and second end portions 433, 431. The first end portion 433 has an engaging surface 434 that is disposed proximate to the inner flange surface of the radial inward flange 113 when the base seat 41 is inserted into the mounting tube 111, and a curved surface 435 that is opposite to the engaging surface 434, and that abuts against the radial inward flange 113 and that permits movement of the retaining member 43 to a disengaging position when the retaining wall 412 is extended through the radial inward flange 113 during insertion of the base seat 41 into the mounting tube 111.
Each retaining member 43 is movable between an engaging position, where the engaging surface 434 of the first end portion 433 of the retaining member 43 abuts against the inner flange surface of the radial inward flange 113 such that the retaining member 43 and the face plate 411 cooperate to retain the base seat 41 in the mounting tube 111, as shown in
The rotary member 45 is disposed rotatably in the receiving space 413, and is formed with a slot 455 to engage removably the release key 5. The rotary member 45 is coupled to the second end portions 431 of the retaining members 43 such that rotation of the rotary member 45 results in movement of the retaining members 43 between the engaging and disengaging positions.
The release key 5 includes an enlarged handle portion 51, a connecting stem 52 extending from the handle portion 51, and a control portion 53 connected to a distal end of the connecting stem 52. The release key 5 is to be inserted into the insert hole 414 in the face plate 411 of the base seat 41, engages removably the slot 455 in the rotary member 45, and is operable so as to drive rotation of the rotary member 45 relative to the base seat 41.
In this embodiment, the second end portions 431 of the retaining members 43 extend into the receiving space 413, and are disposed between the face plate 411 and the rotary member 45. The rotary member 45 includes a circular body 451 formed with a pair of cam surfaces 453 that act upon the second end portions 431 of the retaining members 43 such that rotation of the rotary member 45 due to operation of the release key 5 results in movement of the retaining members 43 between the engaging and disengaging positions. The circular body 451 is further formed with a pair of curved limit plates 452 that cooperate with the stop blocks 419 in the receiving space 413 to limit extent of angular rotation of the rotary member 45 relative to the base seat 41. Preferably, the slot 455 in the rotary member 45 is confined by a pair of slot-confining walls 454, which project from the circular body 451.
Each cam surface 453 of the rotary member 45 defines a corresponding cam hole, and includes a linear section 456 proximate to the center of the circular body 451 and having first and second end points, the first end point being disposed farther from the center of the circular body 451 than the second end point, a curved section 457 that extends counterclockwise from the first end point, and an inclined section 458 that extends from the second end point and that is connected to the curved section 457. The second end portion 431 of each retaining member 43 is formed with a cam post 432 that extends into the cam hole defined by the corresponding cam surface 453 and that abuts against the cam surface 453.
The inner cap 46 is formed with a pair of posts 461 that engage the mounting holes 418 in the retaining wall 412 so as to mount the inner cap 46 on the retaining wall 412, thereby closing the receiving space 413 and thereby retaining rotatably the rotary member 45 in the receiving space 413.
The outer cap 47 is mounted detachably on the base seat 41 to cover the insert hole 414. In this embodiment, the outer cap 47 is made of a magnetically attractive material, and is attracted to the base seat 41 by means of the magnets 42 disposed in the magnet recesses 415.
Referring once again to
Referring to
When the alarm actuator 4 is mounted in the through hole 112 in the mounting member 1, access to the keyhole 21 in the lock member 2 is not possible. When operated in the armed mode, the alarm circuit 31 generates an alarm output in response to detection by the first contact member 32 of removal of the alarm actuator 4 from the through hole 112 in the mounting member 1, thereby discouraging picking of the lock member 2.
Referring to
To mount the alarm actuator 4 in the through hole 112, it is only required to push the former into the latter. As the retaining members 43 move into the through hole 112, the curved surfaces 435 thereof initiallyabut against the radial inward flange 113, thereby moving the retaining members 43 to the disengaging position. Subsequently, after the curved surfaces 435 have moved past the radial inward flange 113, the retaining members 43 are restored to the engaging position by virtue of the biasing members 44.
The alarm device of this invention is applicable to a battery-operated electric lock with a key-operated mechanism. While the electric lock has a relatively large electrical power requirement for driving locking and unlocking operations thereof, the electrical power required to arm and disarm the alarm circuit 31 is relatively small. Hence, while the residual power of a battery source may be inadequate for electrical operation of the electric lock, it is still sufficient to permit disarming of the alarm circuit 31.
As mentioned hereinabove, when operated in the armed mode, the alarm circuit 31 generates an alarm output in response to detection by the first contact member 32 of removal of the alarm actuator 4 from the through hole 112 in the mounting member 1, thereby discouraging picking of the lock member 2. On the other hand, if a burglar tries to break the alarm device of this invention, the alarm actuator 4 will be displaced toward the second contact member 33. Hence, during operation in the armed mode, the alarm circuit 31 further generates the alarm output when the second contact member 33 contacts the alarm actuator 4, thereby discouraging breaking of the alarm device of this invention.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
