Multi-piece hinge cap with sloped surfaces for ligature resistance

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Solution Overview

Problem

Geared continuous hinges in doorways are vulnerable to misuse, which can lead to damage or self-inflicted injury, particularly in institutional settings where inmates may hang objects from the exposed top surfaces, necessitating a solution for ligature resistance.

Innovation Solution

A multi-piece hinge cap system comprising a frame cap and a door cap with downward sloping upper surfaces that cover the exposed upper surface of the geared continuous hinge, preventing misuse by creating a continuous sloped surface that slopes downward from the door frame and door, thereby deterring hanging or abusive use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a unitary hinge cap is attached to overlay the exposed top surface of the geared continuous hinge, then the hinge provides ligature resistance and prevents misuse, but the cap creates sharp edges and horizontal supportive areas that can be used for hanging objects

Engineering Contradiction:

Improveligature resistanceVSAvoidsharp edges and horizontal supportive areas

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The hinge cap is divided into multiple segments: a frame cap attached to the door frame and a door cap attached to the door. These segments create a multi-piece configuration that eliminates continuous horizontal surfaces while maintaining ligature resistance through the segmented structure and downward slopes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hinge cap features downward sloping surfaces that replace flat horizontal surfaces. The sloped configuration prevents objects from being supported or hung, eliminating the harmful horizontal supportive areas while maintaining the protective function through curved or angled geometry.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Area of stationary object

If the hinge cap has a flat upper surface to cover the hinge, then it provides coverage, but the flat surface can support objects and enable abusive use

Engineering Contradiction:

Improvecoverage areaVSAvoidhorizontal supportive areas

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The cap transitions from a flat upper surface to downward sloping surfaces. This geometric change maintains the coverage area over the hinge while eliminating the horizontal supportive characteristics that enable abusive use. The sloped surfaces provide coverage without creating platforms for hanging objects.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Strength

If fasteners are used to mount the frame cap and door cap, then the caps are securely attached, but the fastener heads can be used for hanging objects

Engineering Contradiction:

Improvemounting strengthVSAvoidfastener head protrusions

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The fastener heads are nested within recessed portions of the frame cap and door cap. This nesting conceals the fastener heads and prevents them from protruding outward, eliminating the harmful protrusions that could be used for hanging objects while maintaining secure attachment through the recessed mounting structure.

Inventive Principle:

Principle #7Nested doll (Nesting)

4Ease of manufacture

If the frame cap and door cap are designed as separate pieces, then they can be installed independently on the door frame and door, but the interface between them may create gaps or misalignment

Engineering Contradiction:

Improveinstallation flexibilityVSAvoidinterface alignment

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The frame cap and door cap are designed with asymmetric features including recessed portions and curved interface lines. The recessed portions accommodate fasteners and the curved interface lines guide proper alignment during installation. These asymmetric design elements ensure stable composition and proper alignment while maintaining the flexibility of separate piece installation.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS10633899B2Multi-piece top cap for a geared continuous hinge

Publication Date: 2020.04.28 SELECT PRODUCTS LTD

AI summary

A multi-piece hinge cap covers an upper surface of an installed geared continuous hinge to provide ligature resistance with a door supported by the installed geared continuous hinge in a closed position. The multi-piece hinge cap has a frame cap that attaches at a vertical member of a door frame above a frame leaf of the installed geared continuous hinge. Also, the multi-piece hinge cap has a door cap that attaches at the door adjacent to the frame cap and above a door leaf of the installed geared continuous hinge. The frame and door caps each include an upper surface having a downward sloping angle that slopes downward from the door frame and the door, respectively, and extends over the exposed upper surface of the installed geared continuous hinge.