Door Closer Clutch Assembly for Safe Spring Tension Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current door closers for commercial refrigerators and freezers are difficult to adjust, as the process of changing spring tension is time-consuming, tedious, and potentially dangerous due to the risk of over-tensioning and spring breakage, and requires manual manipulation of the torque arm and catch.
Innovation Solution
A door closer design featuring a clutch assembly with interlocking discs that limits rotational movement to prevent over-tensioning of the spring, allowing for incremental adjustment of spring tension without manual manipulation of the door or catch, using a ratchet assembly and indexing mechanism for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spring tension is manually adjusted by moving the rod and pushing the door while moving a catch to lock the position, then the door closing tension can be adjusted, but the adjustment process becomes time-consuming, tedious, and potentially dangerous due to the risk of spring breakage
Solution Approach 1:
The door closer system performs self-adjustment of spring tension through an automated mechanism. The motor rotates the torque arm to index positions, and the spring tension is automatically adjusted without requiring manual manipulation of the rod and catch by an installer, making the system serve itself in the adjustment process
Solution Approach 2:
The manual mechanical adjustment system (rod, catch, and manual door pushing) is replaced with an automated motor-driven system. The motor rotates the torque arm to predetermined indexed positions, automatically adjusting spring tension without the need for manual mechanical manipulation, thereby eliminating the safety risks and time consumption associated with manual adjustment
2Adaptability or versatility
If the torque arm is incrementally rotated to index the spring tension, then the closing strength can be varied, but the installer may over-index or over-tension the spring causing the spring to break
Solution Approach 1:
The system pre-determines safe indexed positions for the torque arm where spring tension is guaranteed to be within safe limits. The motor rotates the torque arm to these predetermined positions before the spring could potentially be over-tensioned, preventing spring breakage before it can occur
Solution Approach 2:
The indexing mechanism provides feedback control by stopping the torque arm at predetermined positions that correspond to safe spring tension levels. The motor receives feedback about the torque arm position and automatically stops at indexed positions, preventing over-tensioning through closed-loop control
3Ease of operation
If the door closer includes adjustment features with manual manipulation of the rod and catch, then the spring tension can be adjusted, but the adjustment method becomes complex and potentially dangerous
Solution Approach 1:
The door closer automatically adjusts spring tension through motor-driven rotation of the torque arm to indexed positions. The system serves itself by eliminating the need for manual manipulation of adjustment components, simplifying the operation for the installer while reducing overall system complexity through automation
Solution Approach 2:
The system changes the adjustment parameter from manual position setting to automated indexed positioning. The motor drives the torque arm to predetermined angular positions that correspond to specific spring tension values, transforming the adjustment process from a complex manual manipulation task to a simple automated parameter selection
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
Enables safe and efficient adjustment of door closing tension, preventing spring breakage and simplifying the adjustment process, ensuring proper sealing and closing of the door without the risk of over-tensioning.
Implementation Method 1
These door closers include a spring to actuate the door closing movement. The tension in the spring may be adjusted to vary the closing strength of the door closer
Implementation Method 2
The clutch assembly including a first clutch disc and a second clutch disc rotationally and releasably engaging the first clutch disc. The rotational movement of the spring shaft is limited by the engagement of the clutch assembly to prevent over tensioning of the spring
Data Source
AI summary
A door closer (10) includes an exterior housing (11), a spring assembly (12), a ratchet assembly (13), and a clutch assembly (14). The housing has a central tube (17), drive collar (23), a top end cap (52), and a bottom end cap (65). The drive collar includes an indexing pin channel (41) and indexing pin (42) which includes a pawl (45) having a contact surface (47) and a curved bearing surface (48). The spring assembly includes a shaft (73), a spring stop (80), and a helical torsion spring (106) positioned upon the shaft. The ratchet assembly resides within drive collar and includes ratchet wheel (111) having an annular array of ratchet teeth (112) configured to mesh with the pawl of the indexing pin. Each tooth has an undercut contact surface (113) and a curved bearing surface (114). The clutch assembly includes a bottom disc (120) and a top disc (121).