Scissor-Blocking Exit Device for Integrated Delayed Egress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional delayed egress systems require separate units like maglocks, increasing wiring and installation complexity, and there is a need for improved exit devices that address these issues.
Innovation Solution
A scissor mechanism-based exit device with a blocking member and driver mechanism that selectively prevents inward scissoring movement, allowing for delayed egress control without additional units, using a pushbar to actuate the latch mechanism after a predetermined delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional delayed egress systems use maglocks, then delayed egress control is achieved, but device complexity and wiring requirements increase
Solution Approach 1:
The patent combines the blocking function and scissor mechanism into a single integrated exit device unit. The blocking member is mounted on the scissor mechanism itself, allowing the device to provide delayed egress control without requiring separate maglock units or additional wiring systems. This integration directly reduces device complexity while maintaining the delayed egress control function.
Solution Approach 2:
The scissor mechanism serves multiple functions: it provides the delayed egress control through the blocking member, acts as the latch mechanism, and enables the pushbar operation. This multi-functionality eliminates the need for separate dedicated components for each function, thereby reducing overall device complexity and wiring requirements.
2Reliability
If a blocking member prevents inward scissoring movement, then delayed egress control is achieved, but ease of operation may be reduced
Solution Approach 1:
The blocking member is designed to be dynamically controllable through the driver mechanism. During normal operation, the blocking member prevents inward scissoring to maintain security. When egress is needed, the driver actuates the blocking member to move it out of the way, allowing the scissor mechanism to scissor inward and the pushbar to operate. This dynamic control maintains both security and ease of operation.
Solution Approach 2:
The driver mechanism acts as an intermediary between the user's pushbar operation and the blocking member. The driver receives the user's input through the pushbar and translates it into the appropriate action to move the blocking member, ensuring that the user experiences smooth, easy operation while the blocking member provides the necessary delayed egress control.
Data Source
AI summary
An exemplary exit device generally includes a pushbar, a scissor mechanism, a blocking member, and a driver. The pushbar is mounted for movement between a projected position and a depressed position. The scissor mechanism is connected between the pushbar and a latch mechanism, and depression of the pushbar causes an inward scissoring movement of the scissor mechanism and actuation of the latch mechanism. The blocking member is mounted for movement between a blocking position, in which the blocking member prevents the inward scissoring movement, and an unblocking position, in which the blocking member does not prevent the inward scissoring movement. The driver is operable to move the blocking member between the blocking position and the unblocking position.