Introduction
This manual provides detailed instructions for the assembly, operation, and maintenance of your DUMOS Ergonomic High Back Office Chair. Please read this manual thoroughly before assembly and use to ensure proper function and longevity of your chair.
Image: The DUMOS Ergonomic High Back Office Chair, light grey with black frame, positioned at a desk in a modern office environment.
Safety Information
Important Safety Precautions:
- Always follow the assembly instructions provided in this manual.
- Do not exceed the maximum weight capacity of 300 lbs (136 kg). Exceeding this limit may cause damage to the chair and potential injury.
- Ensure all screws and bolts are securely tightened before use. Periodically check and re-tighten as necessary.
- Keep hands and fingers clear of moving parts during adjustment.
- Use the chair on a flat, stable surface.
Package Contents
Before beginning assembly, verify that all components are present and undamaged. If any parts are missing or damaged, please contact customer support.
- Backrest (1)
- Seat Cushion (1)
- Armrests (2)
- Gas Lift Cylinder (1)
- Star Base (1)
- Casters (5)
- Mechanism Plate (1)
- Hardware Pack (screws, washers, Allen wrench)
Setup and Assembly
Assembly typically takes 10-15 minutes. All necessary hardware and tools are included. For visual guidance, refer to the included installation instructions and videos provided with your purchase.
- Attach Casters to Base: Insert each of the five casters into the holes at the end of each leg of the star base until they click securely into place.
- Install Gas Lift: Place the gas lift cylinder into the center hole of the star base.
- Attach Mechanism Plate to Seat: Align the mechanism plate with the screw holes on the underside of the seat cushion. Ensure the front of the mechanism faces the front of the seat. Secure with screws using the provided Allen wrench.
- Attach Armrests to Seat: Secure the armrests to the sides of the seat cushion using the designated screws. Ensure they are oriented correctly for the flip-up function.
- Attach Backrest to Seat/Armrests: Connect the backrest to the seat and armrests using the remaining screws.
- Connect Seat Assembly to Gas Lift: Carefully place the assembled seat onto the gas lift cylinder, ensuring it is centered and stable.
Operating Instructions
Your DUMOS Ergonomic Office Chair offers several adjustable features to customize your seating experience.
1. Seat Height Adjustment
To adjust the seat height, locate the lever on the right side beneath the seat. While seated, pull the lever up to lower the seat. To raise the seat, stand up and pull the lever up. Release the lever at your desired height.
Image: Visual representation of the chair's tilt and rocking mechanism, including recline lock, rocking tension, and height adjustment controls. Shows chair positions for 90° work, 105° rest, and 120° sleep.
2. Tilt and Rocking Function
The chair features a 90°-120° tilt function, ideal for transitioning between work and relaxation. Locate the lever on the left side beneath the seat.
- To Recline: Pull the lever outwards to unlock the tilt mechanism. Lean back to your desired angle and push the lever inwards to lock the position.
- To Adjust Rocking Tension: The round knob located at the front center beneath the seat controls the rocking tension. Turn clockwise to increase tension (making it harder to recline) or counter-clockwise to decrease tension (making it easier to recline).
3. Flip-Up Armrests
The armrests can be flipped up to allow the chair to be pushed closer to a desk or for space-saving storage. Simply lift the armrests upwards until they lock into a vertical position. To return them to the horizontal position, pull them down.
Image: The DUMOS office chair with its armrests shown in both the standard down position and flipped up, illustrating the space-saving feature.
Maintenance
Regular maintenance will help preserve the appearance and functionality of your chair.
- Cleaning: Wipe the chair surfaces with a damp cloth. Avoid harsh chemicals or abrasive cleaners, which may damage the mesh fabric or cushion material.
- Hardware Check: Periodically check all screws and bolts to ensure they remain tight. Re-tighten as needed to prevent loosening and ensure stability.
- Caster Care: Keep casters free of hair and debris to ensure smooth rolling.
Troubleshooting
If you encounter any issues with your DUMOS Ergonomic Office Chair, refer to the following common solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Chair does not adjust height | Gas lift lever not engaged or gas lift cylinder faulty. | Ensure the height adjustment lever is fully pulled up. If the issue persists, the gas lift cylinder may need replacement. |
| Chair wobbles or feels unstable | Loose screws or uneven floor. | Check and tighten all assembly screws. Ensure the chair is on a flat, even surface. |
| Casters do not roll smoothly | Debris caught in casters or casters damaged. | Remove any hair or debris from the caster wheels. If damaged, casters may need replacement. |
| Backrest does not recline or lock | Tilt lock lever not engaged or mechanism faulty. | Ensure the tilt lock lever is properly engaged or disengaged. Adjust rocking tension knob. |
Specifications
Image: Technical drawing illustrating the dimensions of the DUMOS Ergonomic Office Chair, including seat height, depth, width, and overall chair height.
| Feature | Detail |
|---|---|
| Brand | DUMOS |
| Model Name | Ergonomic Office Chair |
| Item Model Number | HJ3-BL-C-3699-GY |
| Color | Light Grey |
| Product Dimensions | 20.08"D x 20.47"W x 48.03"H |
| Overall Size | 25.59" x 26.38" x 48.03" |
| Maximum Weight Recommendation | 300 Pounds (136 kg) |
| Back Style | Solid Back, S-shaped ergonomic design |
| Special Feature | Ergonomic, Adjustable Height, Flip-up Armrests, Tilt Function (90°-120°) |
| Arm Style | Flip-up |
| Fill Material | High-density shaping foam (cushion) |
| Surface Recommendation | Hard Floor (PU casters) |
| Assembly Required | Yes |
| Item Weight | 27.6 pounds (12.5 kg) |
Warranty and Support
For any questions, concerns, or assistance with your DUMOS Ergonomic Office Chair, please refer to the following resources:
- User Manual (PDF): A comprehensive PDF version of this manual is available for download here.
- Customer Service: Contact DUMOS customer support for further assistance. Refer to your purchase documentation for specific contact details.
Please retain your proof of purchase for warranty claims, if applicable. Specific warranty terms may vary; consult your purchase receipt or product packaging for details.
