Office Swivel Chair Backrest Biasing Using Rear Seat Load
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Solution Overview
Problem
The existing swivel chair mechanisms inefficiently utilize the weight of a person, as the energy accumulator is loaded over the front region of the seat, limiting the effective engagement of the backrest support and requiring manual adjustment for pretensioning.
Innovation Solution
A tension or compression spring-based energy accumulator engages the backrest support via a transverse connector, with a movable mounting system allowing adjustment of the effective distance, enabling the full weight of the person to be utilized for tensioning and varying the pretensioning of the backrest, potentially using an elastic or flexible cover as the accumulator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the energy accumulator is connected via a two-armed lever to the front edge of the seat, then the mechanism can be constructed, but the weight of the person cannot be effectively utilized because the loading occurs over the front region (thigh region) rather than the rear region where maximum weight is applied
Solution Approach 1:
The patent relocates the energy accumulator from the front region to the rear region of the seat, changing the spatial dimension of force application. This allows the accumulator to engage with the backrest support at an effective distance from the pivot axis, utilizing the maximum weight applied by the person's body in the rear region rather than the thigh region.
Solution Approach 2:
The patent introduces a transverse connector as an intermediary element that connects the energy accumulator to the backrest support. This mediator allows the accumulator to be actuated by the person's weight while simultaneously providing the biasing force to the backrest, enabling efficient weight utilization without direct rigid connection.
2Productivity
If the energy accumulator is positioned to engage the backrest support at an effective distance from the pivot axis, then the leverage and tensioning efficiency is optimized, but the device complexity increases due to the transverse connector and movable mounting system
Solution Approach 1:
The transverse connector serves multiple functions: it connects the energy accumulator to the backrest support, provides the effective distance for leverage, and allows for adjustment of the mounting position. This multi-functionality optimizes mechanism efficiency while managing structural complexity by consolidating several functions into a single component.
Solution Approach 2:
The patent implements a movable mounting system that allows the energy accumulator to be adjusted along the transverse connector. This dynamic adjustment capability enables optimization of the effective distance for different usage scenarios, improving mechanism efficiency while maintaining adaptability rather than requiring multiple fixed configurations.
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
This configuration allows for effective utilization of the seated person's weight to bias the backrest, eliminating the need for manual adjustment and enhancing the efficiency of the mechanism by optimizing the leverage and tensioning based on the person's weight distribution.
Implementation Method 1
an energy accumulator (9) which, on loading of the seat (5), is tensioned and acts on the backrest support (3)... The energy accumulator is a tension spring... By a load on the seat the two-armed lever is pivoted, the tension spring thereby being tensioned
Implementation Method 2
The energy accumulator may be a compression spring
Implementation Method 3
The seat may comprise an elastic cover which is clamped on the one side in the support member and on the other side is connected to the backrest support. The elastic cover serves as an energy accumulator.
Implementation Method 4
The seat may also comprise a flexible cover connected on the one side to the energy accumulator and on the other side to the backrest support
Data Source
AI summary
A chair comprises a seat and a backrest support which are mounted on a support member, the backrest support being pivotal about a horizontal pivot axis, and an energy accumulator which is tensioned when the seat is subjected to a load and acts on the backrest support, the energy accumulator engaging the backrest support at an effective distance from the pivot axis.To improve the efficiency of such a mechanism, the energy accumulator is connected on the one side to the support member and one the other side via a transverse connector to the backrest support.With the mechanism the energy accumulator is subject to a load substantially by the rear region of the seat and thus substantially by the complete weight of a person sitting on the seat.In an alternative embodiment the seat comprises an elastic cover which on the one side is clamped in the support member and on the other side is connected to the backrest support, the elastic cover serving as energy accumulator.According to a further alternative the seat comprises a flexible cover which is connected on the one side to the energy accumulator and on the other side to the backrest support.