Patent Application
20140035301
This invention relates to a strike for an electromechanical lock used on a prison cell door, and more particularly to a strike that precludes foreign material from being stuffed into the strike to defeat the lock.
A door for a prison cell has a lock, which typically includes an electromechanical latch with a latch bolt positioned in the door jamb and a corresponding strike positioned on the cell door. The conventional strike includes a strike faceplate for attaching the strike to the door and a strike box with a strike opening for accommodating the latch bolt. In order to defeat a conventional lock on a prison cell door, prison inmates on occasion stuff foreign material through the strike opening into the strike box so that when the cell door closes, the latch bolt cannot fully engage the strike opening thereby leaving the cell door unsecured.
In order to overcome the problem presented by prison inmates stuffing foreign material into the strike box of the strike, the strike of the present invention includes a spring-loaded ejector plate slidably mounted within the strike box for ejecting foreign materials from the strike box while at the same time giving the prison guard a visual indication that the strike box is clear of foreign materials. The ejector plate includes cylindrical rods that engage holes in the end wall of the strike box so that the ejector plate can slide fore and aft in the strike box. The ejector plate is spring-loaded by springs that urge the ejector plate within the strike box toward the strike opening. When the electromechanical latch is closed, the latch bolt of the electromechanical latch forces the ejector plate into the strike box against the force of the springs of the ejector plate. When the electromechanical latch is opened and the latch bolt is withdrawn, the springs push the ejector plate toward the strike opening. Consequently, an attempt to stuff foreign material into the exposed strike box is foiled by the spring-loaded ejector plate ejecting the foreign material from the strike box.
In addition, the front face of the ejector plate is painted a bright color, such as green, so that a prison guard can tell at a glance whether the ejector plate is extended and the strike box is clear. Further, the inside of the strike box may be coated with a slippery material, such as a Teflon brand coating, making it difficult for foreign materials to be retained in the strike box against the spring force of the ejector plate.
Further objects, features and advantages will become apparent upon consideration of the following detailed description of the invention when taken in conjunction with the drawings and the appended claims.
The electromechanical latch 16 includes the latch bolt 18 which, in conventional fashion, extends to engage the opening 36 of the strike 20 in order to hold the cell door closed, and retracts from the strike 20 in order to allow the cell door to open. The latch bolt 18 may be spring biased toward the extended position or may be mechanically driven by the electromechanical mechanism toward the extended position.
With reference to
With reference to
The ejector plate 38 and the strike box 24 are dimensioned so that the ejector plate 38 fits within the strike box 24 with minimum sliding clearance between the edges of the ejector plate 38 and the side walls 26, the top wall 28, and the bottom wall 30 of the strike box 24. Other mechanisms for mounting the ejector plate 38 within the strike box 24 may be employed to allow the ejector plate 38 to slide fore and aft within the strike box 24.
The front face 46 of the ejector plate 38 is brightly colored. In addition, the internal surfaces of the side walls 26, the top wall 28, and the bottom wall 30 are low friction surfaces, such as Teflon brand coated surfaces.
In operation, the ejector plate 38 operates to thwart inmates from stuffing foreign material into the strike box 24 when the strike 20 is exposed and thus defeat the lock 14. When the electromechanical latch 16 is closed, the latch bolt 18 of the electromechanical latch 16 forces the ejector plate 38 into the strike box 24 against the combined force of the springs 42. Consequently, the extending force of the latch bolt 18 must be sufficient to overcome the combined force of springs 42. When the electromechanical latch 16 is opened and the latch bolt 18 is withdrawn, the combined force of the springs 42 push the ejector plate 38 toward the strike opening 36. While the strike opening 36 is exposed, an attempt to stuff foreign material into the strike box 24 will be unsuccessful because the combined force of springs 42 on the ejector plate 38 will eject foreign materials from the strike box 24. In addition, because the internal surfaces of the side walls 26, the top wall 28, and the bottom wall 30 are low friction, the ability of the ejector plate 38 eject foreign materials from the strike box 24 is enhanced.
In addition, because the outside face 46 of the ejector plate 38 is painted a bright color, such as green, a prison guard can tell at a glance whether the ejector plate 38 is extended and the strike box 24 is clear.
While this invention has been described with reference to preferred embodiments thereof, it is to be understood that variations and modifications can be affected within the spirit and scope of the invention as described herein and as described in the appended claims.
This invention claims priority from U.S. Provisional Patent Application No. 61/677,574, filed Jul. 31, 2012, which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61677574 | Jul 2012 | US |
