Safety Switching Device Control Disk Bolt Interlock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Safety switching devices for protective devices, such as motor or industrial robot doors, fail to adequately secure against high tensile forces, leading to the destruction of the locking mechanism and potentially allowing the system to operate with the protective device open.
Innovation Solution
A safety switching device with a control disk actuated by a bolt, featuring an incision on its circumference that engages a transverse web, and a locking pin system with an additional pin for bending load absorption, along with a locking mechanism activated by an electromagnet or tensioned spring, ensuring the bolt is blocked from being pulled out even under extreme forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional locking mechanism with a single locking bolt is used, then the device structure is simple, but the device cannot withstand high tensile forces and may fail under extreme loads
Solution Approach 1:
The locking mechanism is divided into multiple independent locking bolts (first locking bolt and second locking bolt) that act on different sides of the control disk. This segmentation allows each bolt to bear portion of the tensile load, collectively providing resistance to forces up to 2400 N while maintaining a relatively simple overall structure.
Solution Approach 2:
Multiple locking bolts are combined to work together on the same control disk, creating a redundant locking system. The first locking bolt and second locking bolt both engage with the control disk's locking groove, providing combined strength against tensile forces that exceeds the sum of individual bolt capabilities.
2Strength
If the locking bolt is made longer to increase engagement, then the tensile strength improves, but the device dimensions increase
Solution Approach 1:
Instead of uniformly increasing the length of a single locking bolt, the invention applies locking engagement at multiple local positions around the control disk circumference. The first and second locking bolts engage at different angular positions, providing distributed local engagement that achieves high overall strength without requiring excessive individual bolt length.
Solution Approach 2:
The locking approach transitions from a single-dimensional (one bolt, one engagement point) to a multi-dimensional configuration where locking bolts are arranged angularly around the control disk. This spatial distribution in multiple dimensions provides enhanced cumulative strength without increasing the length of individual bolts.
3Reliability
If an electromagnetic locking mechanism is added to reinforce the device, then the security against high forces improves, but the energy consumption and device complexity increase
Solution Approach 1:
The invention replaces electromagnetic locking mechanisms with a purely mechanical redundant bolt system. The first and second locking bolts provide mechanical engagement with the control disk, eliminating the need for electromagnetic actuators while achieving equivalent or superior reliability against high forces. This mechanical approach consumes no energy during the locking function.
Solution Approach 2:
The locking system is designed to be self-sustaining through mechanical engagement of multiple bolts with the control disk's locking groove. The system does not require external energy input to maintain the locked state, as the mechanical geometry and friction of the engaged bolts naturally prevent unauthorized release, providing energy-independent security.
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 device provides a significantly higher level of security against unusually strong forces, exceeding DIN EN 1088 by approximately 30%, preventing the bolt from being pulled out and maintaining the locked state even under tensile loads up to 2400 N, thus ensuring the protective device remains secure.
Implementation Method 1
when the advance of the locking bolt is activated (by means of an energized holding magnet)
Implementation Method 2
The feed (locking of the locking bolt) can be applied by the force of a tensioned spring
Data Source
Figure 1~2
Figure 3~4
Figure 5A~6
AI summary
In the case of safety switching devices, the interlock may be destroyed if particularly high tensile forces acting on the operating bolt 32 occur, thus rendering the protection device inoperative. What is proposed is that the design be reinforced, leading to a new configuration of the control disc 10. The control disc is operated by the bolt 32 and can be pivoted about an axis 11' between a first position (release) and a second position (interlock). The control disc has an internal area 14 in which the blocking bolt end 21 ends. The control disc has an incision 12 which is formed on the circumference and whose position with respect to the bolt shaft 30 is such that the lateral web 34 of the bolt engages in the incision, and a complete incision operation of the bolt results in rotation to the second position (interlock) of the control disc, and, when the bolt 32 is in the inserted end position and on activation of the feed of the blocking bolt, the blocking bolt end 21 enters the window 36 and prevents the bolt from being pulled out, and the blocking bolt end leaves the window on deactivation of the feed.