Self-locking Shutter Cam Mechanism for Vandal Resistance
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Solution Overview
Problem
Existing self-service terminal (SST) shutters are vulnerable to unauthorized access and damage from vandalism, as they rely on mechanisms like worm drives and motors that can be compromised during forced attempts to open them.
Innovation Solution
A shutter assembly comprising a shutter blade supported by an end plate, a cam driver with a cam pin that traverses a curved cam slot in the end plate, and a cam shaft mounted to a frame in the SST, which locks the shutter in a closed position and opens it as the cam pin rotates through the cam slot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a worm drive and motor are positioned near the front of the shutter, then the shutter can be moved between open and closed positions, but the drive and motor are subject to damage during an attack by a vandal attempting to force open the shutter
Solution Approach 1:
The patent removes the motor and drive mechanism from the shutter assembly itself and relocates them to a fixed position on the frame. This extraction separates the vulnerable moving components from the shutter blade, protecting them from vandalism while maintaining operational functionality through the cam-driven mechanism.
Solution Approach 2:
Instead of directly coupling the motor to the shutter blade, the patent inverts the traditional drive mechanism by using a cam driver that converts rotational motion into the desired shutter movement through a cam slot and follower arrangement. This indirect coupling protects the motor from direct exposure to vandalism attempts.
2Reliability
If the cam pin and cam slot are configured to lock the shutter blade in a closed position, then unauthorized access is prevented, but the mechanism complexity increases
Solution Approach 1:
The patent achieves reliable locking through careful geometric design of the cam slot curvature and positioning of the cam pin. By optimizing the shape and orientation parameters of the cam mechanism, the system provides secure locking without requiring additional complex components or control systems.
3Strength
If upward force applied to the shutter blade is applied via the cam pin transverse to the cam slot, then force is distributed to minimize rotational stress on the cam shaft, but the cam slot curvature must be precisely designed
Solution Approach 1:
The patent employs a precisely curved cam slot with specific geometric properties that guide the cam pin's movement path. The curvature is designed to convert upward force on the shutter blade into transverse force on the cam shaft, optimizing force distribution and minimizing rotational stress while maintaining manufacturability through defined geometric parameters.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents unauthorized access by securely locking the shutter in a closed position and minimizing damage from vandalism, as the cam mechanism distributes force transversely to the cam shaft axis, reducing rotational stress on the shutter and its components.
Implementation Method 1
a cam driver having a cam pin positioned to traverse a cam slot in the end plate of the shutter blade, the cam pin and cam slot configured to lock the shutter blade in a closed position, and configured to open the shutter blade as the cam pin traverses the cam slot
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
A device (100) includes a shutter blade (210) supported by an end plate (110 or 111) and a cam driver (130 or 131) having a cam pin (135) positioned to traverse a slot (140) in the end plate (110 or 111) of the shutter blade (210), the cam pin (135) and slot (140) acting to lock the shutter blade (210) in a closed position, and operating to open the shutter blade (210) as the cam pin (135) traverses the slot (140).