Mechanical Locking Device for Electrical Switches
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Solution Overview
Problem
In industrial environments, existing mechanical locking devices for electrical switching devices are not suitable for ensuring that production machines are not switched on without a process controller being active, and vice versa, particularly in applications where precise switching sequences are required for voltage supply management.
Innovation Solution
A mechanical locking device is implemented that couples the drive units of two switches via a power transmission device, such as a Bowden cable, to prevent unauthorized switch positions and ensure that one switch can only be turned on when the other is on, and vice versa, using locking disks and transmission levers to block or release actuation based on the other switch's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical locking device is implemented to ensure switching sequences between switches, then switching safety and sequence control are improved, but device complexity increases
Solution Approach 1:
The locking device is segmented into modular components: locking disks for each switch, transmission levers with locking pins, and a power transmission device (Bowden cable) that couples them. Each locking disk can independently block its associated switch while being mechanically linked to others, allowing distributed control that improves safety without requiring a monolithic complex system.
Solution Approach 2:
The Bowden cable acts as an intermediary power transmission device that mechanically couples the locking disks of multiple switches. It transmits blocking and releasing forces between switches without requiring direct mechanical coupling, thereby simplifying the overall device architecture while maintaining reliable inter-switch dependency control.
2Reliability
If locking means are provided for each switch to block unauthorized switching, then switching sequence control is improved, but ease of operation deteriorates
Solution Approach 1:
The locking pins are designed to dynamically engage with recesses in the locking disks only when the other switch is in the OFF position. When the prerequisite switch is switched ON, the power transmission device automatically releases the locking pins, allowing smooth actuation. This dynamic behavior ensures sequence control while maintaining ease of operation during valid switching sequences.
Solution Approach 2:
The locking device automatically manages its own blocking and releasing states through mechanical coupling via the Bowden cable. When one switch is actuated, the power transmission device self-adjusts to either block or release the other switch based on its position, eliminating the need for manual intervention or complex control systems while ensuring proper sequencing.
3Reliability
If a power transmission device couples the locking means of multiple switches, then inter-switch dependency is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex multi-axis mechanical linkages with a Bowden cable-based power transmission system. The cable runs through guide elements and connects to the locking disks, providing flexible yet reliable force transmission between switches. This substitution reduces mechanical complexity compared to rigid linkages while maintaining robust inter-switch dependency control.
4Manufacturing precision
If locking disks and transmission levers are used to block switch actuation, then switching position control is improved, but ease of manufacture deteriorates
Solution Approach 1:
The locking disks serve multiple functions: they provide the blocking surface for locking pins, act as position indicators for switch states, and serve as mounting points for the Bowden cable connections. The transmission levers similarly function as both locking actuators and mechanical linkages. This multi-functionality reduces the total number of components needed and simplifies assembly while maintaining precise switching position control.
Data Source
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AI summary
The invention relates to an electrical switching device with a mechanical locking device for the switching positions of switches, comprising a first switch (10) and a second switch (12), the switching mechanisms of which can be actuated between a first and a second switching position ON and OFF via respective rotary handles (14, 16) and which each have locking means (18, 20) for blocking actuation of their respective switching mechanism, and a force transmission device (22) which couples the locking means of the two switches together, wherein the locking means (18) of the first switch (10) are configured such that they block actuation of the switching mechanism in the first switching position ON and release actuation of the switching mechanism in the second switching position OFF, and the locking means (20) of the second switch (12) are configured such thatthat in the first switching position ON they release an actuation of the switching mechanism and in the second switching position OFF they block an actuation of the switching mechanism, wherein the locking means (18) of the first switch (10) in the second switching position OFF, via the force transmission device (22), hold the locking means (20) of the second switch (12) in the second switching position OFF in a position in which they block an actuation of the switching mechanism of the second switch (12), and the locking means (18) of the first switch (10) in the first switching position ON, via the force transmission device (22), release the locking means (20) of the second switch (12) in the second switching position OFF, and wherein the locking means (20) of the second switch (12) in the first switching position ON, via the force transmission device (22), hold the locking means (18) of the first switch (10) in the first switching position ON in a position,in which they block the actuation of the switching mechanism of the first switch (10), and the locking means (20) of the second switch (12) in the second switching position OFF release the locking means (18) of the first switch (10) in the first switching position ON via the power transmission device (22).