Recliner char

1. Recliner Chair Mechanism
ENME 473 - Winter 2021 - Group 21
Leena Tanakoor, Levi Roberts, Liam Hunter, Lisa Cai, Long Tran, Long Tran
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2. Research Questions
● What is the minimum force required on the handle (link 2) to activate the mechanism?
● What duration of time does it take for the mechanism to fully extend?
● What is the maximum extended length of the recliner?
● Did the design and simulation replicate the real life model?
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3. Simplifying Assumptions
● All the components are assumed to be rigid, without any bending of the parts.
● It is also assumed that all components were manufactured using proper design
specifications and that they are in perfect working condition.
● Effects of friction are assumed to be negligible.
● Constant load is assumed for the recliner chair.
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4. Mobility
m = 3(links-1) - 2(j1 joins) - (j2
joint) - (redundant constraints)
m = 3(8-1) - 2(10)-0-0
m = 21 - 20
m = 1
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Link # Length (m) Width (m) Thickness (m)
1 0.1524 0.009525 0.00635
3 0.2286 0.009525 0.00635
4 0.127 0.009525 0.00635
5 0.127 0.009525 0.00635
6 0.2286 0.009525 0.00635
7 0.1778 0.009525 0.00635
8 0.0508 0.009525 0.00635
Figure #1: Kinematic Diagram of Recliner Chair Mechanism
Table 1: Dimensions of the Links

5. Loops
Loop 1 - Orange
Loop 2 - Green
Loop 3 - Pink
Loop 4 - Blue
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Figure #2: Posture Analysis and Loop Displaying Entire Mechanism

6. Solidworks Video
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7. Loop Analysis - Position
Analysis was focus on link 7
● Maximum horizontal length: 0.575 m
● Maximum vertical length: 0.1 m
Literature value for fully extended length of the
mechanism:0.53m
The obtained figured verified our expected motion
of link 7.
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Figure #3: Path motion of the leg cushion.
Figure #4: Fully Dimensioned Model of Recliner Chair in Meters

8. Loop Analysis - Velocity
Again the analysis will be focused on link 7
● Max speed: ~0.48 m/s
● The speed oscillate around 0.48 m/s
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Figure #5: Absolute velocity of the leg cushion

9. Kinetic Analysis - Torque
The graph shown represents the output torque of Joint
2 found using simulink.
● The torque graph will be used to determine the
output force acting on the reclining chair handle
as the torque can be represented as a moment
which has a moment arm (Link 2) and a force
which is the input force.
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Figure #6: Partial Kinematic Diagram of
Recliner Chair Mechanism
Figure #7: Output Torque Acting on Joint A

10. Kinetic Analysis - Force
● Joint A on Link 2 represents the recliner
handle.
● Using the output torque graph on simulink, a
force versus time plot is generated.
● The minimum and maximum force to operate
the mechanism can be noted as (6.45N-38.35N)
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Figure #8: Required Input Force on Link 2 vs Time

11. Answer Research Question 1
● What is the minimum force required on the handle (link 2) to activate the mechanism?
Table 2: Comparison of Results for minimum activation force
Recliner Model
Mechanism Result
Experimental Result Literature Value
6.45-38.35 N 8.34 N N/A
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Figure #7: Output Torque Acting on Joint A

12. Answer Research Question 2
● What duration of time does it take for the mechanism to fully extend?
Recliner Model
Mechanism Result
Experimental Result Literature Value
1 s 0.77 s 4.0 s [2]
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Figure #10: Position on the end of link 2
Table 3: Comparison of total extended time

13. Answer Research Question 3
● What is the maximum extended length of the recliner?
Table 4: Comparison of results for the maximum extended length
Recliner Model
Mechanism Result
Experimental
Result
Literature Value
0.57 m 0.61 m 0.53-0.66 m [3]
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Figure #3: Path motion of the leg cushion.

14. Answer Research Question 4
Did the design and simulation replicate the real life model?
● Our model gives a good representation of the real life model.
● Some differences were seen when comparing our results to the experimental and literature values.
● Can be accounted for by the following 3 main reasons:
1. Spring Assistance
2. Load on the recliner during motion
3. Friction in the experimental recliners
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15. Key Findings
● We were successful in creating a model to simulate the moving mechanism of a recliner
chair.
● Found the minimum force and time taken for mechanism activation, as well as the fully
extended length, hence answering our research questions.
● These factors are important for both manufacturers and clients so that they can make better
choices according to their preferences.
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16. References
[1] 2019 Posted by cttsonline On June 7, “Questions To Ask For Success: IT Support Georgetown, TX,” CTTS, Inc. [Online].
Available: https://www.cttsonline.com/2019/06/07/questions-entrepreneurs-need-to-ask-to-succeed/. [Accessed: 12-Apr-2021].
[2]S. H. Freier, “The effect of office chair backrest design on the body’s metabolic response to office work,” Marquette.edu. [Online].
Available: https://epublications.marquette.edu/cgi/viewcontent.cgi?article=1014&context=theses_open. [Accessed: 12-Apr-2021].
[3] “Recliner Fit,” La-z-boy.com. [Online]. Available: https://www.la-z-boy.com/content/recliner-fit. [Accessed: 12-Apr-2021].
[4] “How to Measure Your Space for a Recliner,” Livingspaces.com, 07-Sep-2018.
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17. Thank You for Listening!!
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