High Security Striker Box Assembly Design
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Solution Overview
Problem
Conventional striker plates are vulnerable to powerful kicks due to bending screws, which can lead to the striker plate pivoting inwardly and the latch slipping out, compromising door security despite strong doors and latches.
Innovation Solution
A striker box assembly with a robust box structure, including connected lateral walls, a boot flange, jack flange, and wings, attached to a jack stud with divergent screws for enhanced stability and resistance to lateral movement, and a cover plate with a U-channel design to resist distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional striker plates with screws are used, then the latch can be secured to the door frame, but the screws may bend under powerful kicks allowing the striker plate to pivot inwardly
Solution Approach 1:
The striker plate is divided into multiple segments: a main body portion, an inwardly extending portion with a second opening, and a outwardly extending portion with a first opening. This segmentation allows each portion to independently absorb and distribute impact forces, preventing the entire plate from pivoting inwardly when subjected to powerful kicks.
Solution Approach 2:
The invention extends the striker plate in multiple dimensions by adding inwardly and outwardly extending portions perpendicular to the main body. This three-dimensional configuration creates a more complex load path that prevents simple pivoting motion, as forces must now overcome structural resistance in multiple directions rather than allowing rotation around a single axis.
2Strength
If thicker steel striker plates with extra-long screws are used, then tensile strength is improved, but the screws become levers that can break apart the jamb and studs
Solution Approach 1:
The invention extracts the fastening function from the striker plate body by using separate screws that attach only to the inwardly extending portion, which is already secured to the jamb. This eliminates the need for extra-long screws that would act as levers, as the plate's inherent structural integrity provides the necessary attachment without requiring deep penetration into studs.
Solution Approach 2:
The inwardly extending portion with a second opening serves as a pre-positioned attachment point that distributes fastening loads across a broader area of the jamb. This preliminary structural arrangement cushions against concentrated stresses that would otherwise be transmitted through long screws to the studs, preventing lever-induced damage.
3Ease of operation
If the striker plate is spaced about an inch from the 2x4 stud, then installation is easier, but the screws bend sufficiently to allow the striker plate to pivot inwardly
Solution Approach 1:
The striker plate is segmented into a main body and an inwardly extending portion that specifically engages with the jamb. This separation allows the inwardly extending portion to be optimally positioned for secure attachment to the jamb while maintaining the necessary spacing for installation, and the segmented structure prevents pivoting by distributing forces across distinct structural elements.
Data Source
AI summary
A striker box assembly provides enhanced security when locking a door where the assembly includes a box and a cover plate which are secured to a stud in the frame around the doorway in at least three ways. The first way of securing the assembly is with screws in a jack flange that extends along a lateral side of the stud in flush contact therewith. The second manner is with a screw in the bottom of the box to hold the box firmly against the stud or through shims or a boot that solidly fills any gap between the bottom of the box and the stud. The third way is with offset screws that extend through the cover plate and the box into the stud. The cover plate includes a flange that provides additional strength to resist destructive forces involved when a person attempts to break down a door.