Handheld Work Apparatus Blocking Device Actuation
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Solution Overview
Problem
Existing handheld work apparatuses with blocking devices require complex and potentially accidental unblocking mechanisms, leading to ergonomic and operational challenges.
Innovation Solution
A blocking device with a compulsory guide that requires the actuation element to move in both a first and second actuation direction, where the second direction is perpendicular to the first, ensuring the actuation element is moved out of the housing before being unblocked, preventing accidental unblocking when gripping the handle, and featuring an ergonomic arcuate movement path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the actuation element is arranged on the outer side of the handle for easy access, then ease of operation is improved, but accidental unblocking may occur when the operator grips the handle
Solution Approach 1:
The actuation element requires movement in two dimensions: first perpendicular to the handle axis (second actuation direction) to disengage the blocking contour, then parallel to the handle axis (first actuation direction) to complete unblocking. This two-dimensional activation path prevents accidental unblocking during normal gripping while maintaining accessibility
2Device complexity
If the actuation element moves in a straight line for simple mechanism, then device complexity is reduced, but ergonomic operation is compromised
Solution Approach 1:
The actuation element follows an arcuate movement path instead of a straight line, with the first movement perpendicular to the handle axis and the second movement parallel to it. This curved path is more ergonomic for hand operation while the compulsory guide ensures the sequence is maintained
3Ease of operation
If the actuation element extends beyond the housing in the unblocking position for visibility, then operational status is clear, but accidental unblocking risk increases
Solution Approach 1:
The actuation element's primary movement for unblocking occurs perpendicular to the handle axis rather than extending it beyond the housing in the radial direction. This dimensional change maintains visibility of the unblocking position through the perpendicular displacement while preventing the element from protruding and causing accidental unblocking
Data Source
AI summary
A work apparatus has a motor for driving a tool, an operator-controlled element for the motor and a blocking device. The blocking device has an actuating element having a blocking position and an unblocking position. The operator-controlled element is blocked for the operation of the drive motor when the actuating element is in its blocking position. When shifted from the blocking position into the unblocking position, the actuating element is moved in a first direction and in a second direction. The first direction is into the housing part and the second direction runs perpendicular hereto. A compulsory guide is configured to, during movement of the actuation element in the second direction from the blocking position in a direction toward the unblocking position, initially move the actuation element in a direction opposite to the first direction before the actuation element can be moved in the first direction.