1. Field of the Invention
The present invention relates to apparatuses and methods for detecting a position of a door.
2. Description of the Related Art
Known approaches to monitoring whether a door is open or closed employ a two part magnetic switch or a button type switch, which requires a very intrusive mounting scheme. This mounting scheme involves drilling into the door jamb and the door itself, which is time consuming for an installer and destructive to the door and the door jamb.
Another known configuration uses a flush mounted two part magnetic switch. However, this configuration does not work well with door/jamb configurations in which there is inadequate flush mounting surface between the door and the jamb.
Yet other known configurations employ mechanical switches that are integral to the hinge itself. These solutions have very detailed and elaborate machining and design aspects involving specific hinge designs.
All current solutions for monitoring door open states require switches that are mounted by a combination of drilling and screwing, which is destructive and time consuming for the installer. Thus, problems associated with known door position sensors include having to replace existing door hinges; high manufacturing costs; excessive installation time; and the fact that the sensors are not universal solutions that apply to most door installations and types.
What is neither disclosed nor suggested by the prior art is a door position detecting arrangement that requires no drilling or screwing in order to mount and install the apparatus.
The present invention provides security systems that require low cost and easy to install door contacts to monitor door states for entry and exit doors as well as interior door monitoring. A mechanical switch is mounted by removing a hinge pin from a door that is to be monitored. The pin is inserted through the switch and then into the hinge. The switch includes two lever arms that are respectively spring-biased against the door jamb and against the door surface that faces the door jamb when the door is closed. As the door opens, the lever arms move apart, which causes internal metallic contacts of the switch to slide out of contact with each other. The switch housing encloses the metallic contacts and wires connected thereto. The switch housing has upper and lower halves which are attached to and move with respective ones of the lever arms. A center sleeve may prevent pinching of the hinge pin on the switch housing and may prevent damage to the switch resulting from the force of the hinge pin being reinstalled.
The mechanical hinge pin mounted switch of the present invention may be mounted by removing a hinge pin from a residential or commercial door where the position of the door will be monitored. The pin is inserted through the switch and then placed back in the hinge. The displacement of the pin within the hinge may be minimal and may have no effect on the mechanical strength or operation of the hinge. The lever arms of the switch may be spring loaded so that there is no requirement for using any screws for mounting the switch.
The switch of the present invention may meet all of the criteria for being tamper-proof. The actual switch contacts and wires may be located in a secure area. The switch can be mounted on any one of the door hinges, thereby increasing the difficulty for an intruder to access the lever arms and bypass the switch's operation.
In one aspect, the present invention comprises a door position sensing arrangement including a door hinge having a fixed part and a rotatable part. The fixed part is attached to a door frame, and the rotatable part is attached to a door. The fixed part and the rotatable part conjunctively define a first through-channel. A switch includes a fixed portion and a rotatable portion rotatably coupled to the fixed portion. The fixed portion has a first electrical contact, and the rotatable portion has a second electrical contact. The fixed portion is biased against the fixed part of the door hinge and/or against the door frame. The rotatable portion is biased against the rotatable part of the door hinge and/or against the door. The fixed portion and the rotatable portion conjunctively define a second through-channel aligned with the first through-channel. The fixed portion and the rotatable portion have a first position relative to each other wherein the contacts are electrically connected to each other, and a second position relative to each other wherein the contacts are electrically disconnected from each other. Each of the fixed portion and the rotatable portion of the switch has a respective piece extending laterally therefrom. The switch further includes a coil spring with two opposite ends. Each end engages a respective one of the two pieces. The piece of the fixed portion is biased by the spring against the fixed part of the door hinge and/or against the door frame. The piece of the rotatable portion is biased by the spring against the rotatable part of the door hinge and/or against the door. A hinge pin extends at least partially through the second through-channel of the switch and at least partially through the first through-channel of the hinge. The coil spring is coiled around the hinge pin.
In another aspect of the present invention, a door position sensing arrangement comprises a door hinge including a fixed part and a rotatable part. The fixed part is attached to a door frame, and the rotatable part is attached to a door having an open position and a closed position. The fixed part and the rotatable part conjunctively define a first through-channel. A switch includes a fixed portion and a rotatable portion rotatably coupled to the fixed portion. Each of the fixed portion and the rotatable portion of the switch has a respective piece extending laterally therefrom. The piece of the fixed portion is biased against the fixed part of the door hinge and/or against the door frame. The piece of the rotatable portion is biased against the rotatable part of the door hinge and/or against the door. The switch further includes a spring with two opposite ends. Each end engages a respective one of the two pieces. The fixed portion is biased by the spring against the fixed part of the door hinge and/or against the door frame. The rotatable portion is biased by the spring against the rotatable part of the door hinge and/or against the door both when the door is in the open position and when the door is in the closed position. The fixed portion and the rotatable portion conjunctively define a second through-channel aligned with the first through-channel. Sensing means senses a position of the rotatable portion of the switch relative to the fixed portion of the switch. A hinge pin extends at least partially through the second through-channel of the switch and at least partially through the first through-channel of the hinge.
In still another aspect, the present invention provides a door position detecting apparatus comprising a switch including a body having two electrical contacts and a through-channel. The through-channel of the switch receives a hinge pin inserted therethrough and further inserted into a door hinge. Two lever arms extend from the body. Each of the arms is attached to a respective one of the electrical contacts. The arms have a first position relative to each other wherein the contacts are electrically connected to each other, and a second position relative to each other wherein the contacts are electrically disconnected from each other. Biasing means biases the arms against a fixed door jamb and a rotatable door, respectively, such that one of the arms follows movement of the rotatable door from an open position of the door to a closed position of the door. Monitoring means monitors whether the contacts are electrically connected to each other.
An advantage of the present invention is that it has minimal installation requirements.
Another advantage is that the present invention is simple and inexpensive to manufacture, with a high level of reliability due to its simplicity.
Yet another advantage is that the apparatus of the present invention may require only the existing door hinge and hinge pin as a mounting mechanism.
A further advantage is that the present invention is operable with both wooden and metallic doors since the electrical contacts in the switch are not susceptible to magnetic interference issues.
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
The embodiments hereinafter disclosed are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following description. Rather the embodiments are chosen and described so that others skilled in the art may utilize its teachings.
Referring first to
Referring still to
Stationary portion 24 includes a body 25 (
As illustrated in
Stationary portion 24 and rotatable portion 26 of switch 12 may be formed of a plastic material, and spring 31 may be molded therein. Opposite ends 36, 38 of spring 31 may be molded into lever arms 32, 34, respectively. In another embodiment (not shown), arms 32, 34 each include a respective slot in which a respective opposite end 36, 38 of spring 31 is received.
Referring now to
Stationary portion 24 and rotatable portion 26 may be connected to each other by only spring 31. However, in another embodiment (not shown), bodies 25, 27 may be rotatably coupled together. For instance, lower surface 42 of body 25 may include an arcuate rib that is received in an arcuate groove provided in upper surface 46 of body 27.
In operation, as a person moves door 18 from the closed position, shown in
Electrical conductors, such as wires 54, 56, may be electrically connected to contacts 40, 44, respectively. Wires 54, 56 may be welded to contacts 40, 44, as at 58, 60, respectively. Wires 54, 56 may be electrically connected to an electrical continuity detector 62 (
A cylindrical sleeve 64 may optionally be inserted in through-channel 28 in order to protect bodies 25, 27 from damage that may result from hinge pin 20c being inserted therein. An upper end of sleeve 64 may be provided with a lip (not shown) extending in a radially outward direction in order to latch onto an upper surface 66 (
One embodiment of a method 700 of the present invention for detecting a position of a door is illustrated in
In a next step 704, a hinge pin is inserted through the through-channel of the switch. That is, hinge pin 20c is inserted through through-channel 28 of switch 12.
Next, in step 706, the hinge pin is inserted into a door hinge. For instance, hinge pin 20c may be inserted into door hinge 20.
In step 708, the arms are biased against a door jamb and the door, respectively. More particularly, arms 32, 34 are biased by spring 31 against jamb 16a and door 18, respectively.
Finally, in step 710, it is monitored whether the contacts are electrically connected to each other. In the embodiment disclosed above, electrical continuity detector 62 is connected to each of contacts 40, 44 and monitors whether contacts 40, 44 are electrically connected to each other.
Switch 12 has been illustrated herein as including a fixed portion 24 on top and a rotatable portion 26 on the bottom, i.e., engaging and supported by hinge 20. However, it is to be understood that the present invention also encompasses embodiments in which the switch includes a fixed portion on bottom and a rotatable portion on top.
Switch 12 has also been illustrated herein as including electrical contacts 40, 44 that engage each other when door 18 is closed and that do not engage each other when door 18 is open. However, in another embodiment, the electrical contracts may be in engagement with each other when door 18 is open, and may be out of engagement with each other when door 18 is closed.
Electrical contacts 40, 44 are disclosed herein as being used to determine whether the rotatable portion 26 of switch 12 is in a certain position. However, the scope of the present invention encompasses non-contact types of devices that may determine proximity of an object. For instance, the rotatable portion of the switch may include a magnet, and the fixed portion of the switch may include a magnet sensor for determining whether the rotatable portion is in a certain position.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
This application is a continuation of U.S. patent application Ser. No. 12/270,232 entitled “HINGE PIN MOUNTED DOOR SWITCH” (Attorney Docket No. 13050-414-US-1), filed Nov. 13, 2008. The complete subject matter of this patent application is hereby incorporated herein by reference, in its entirety.
Number | Date | Country | |
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Parent | 12270232 | Nov 2008 | US |
Child | 13539286 | US |