Quick Summary
The Cordless Spring Mechanism is the core architecture that enables bamboo Roman shades to deliver
pull-and-stop operation without external cords.
The T series system integrates a T1 Spring Box (with a constant force spring),
Cord Reel, Cord Bundle, and Fiber Glass Hexagonal Rod to provide
balanced lift assistance, stable holding at any height, and reduced entanglement risk for children and pets.
What Is the T Series Cordless Spring Mechanism?
The Cordless Spring Mechanism for bamboo Roman shades is a fully mechanical lift system designed for
direct bottom-rail operation. The shade moves by winding and unwinding internal lift cords—without external pull cords.
This improves safety, maintains clean aesthetics, and delivers intuitive manual control.
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System Composition
- T1 Spring Box (housing a constant force spring)
- Cord Reel (for controlled cord winding)
- Cord Bundle (for cord fixing and tension adjustment)
- Fiber Glass Hexagonal Rod (for torque transmission and synchronized rotation)
Top Mounting & Shaft Path
The T1 Spring Box and Cord Reel are fixed at the top of the bamboo Roman shade
and locked onto the wooden headrail using screws. A Fiber Glass Hexagonal Rod passes through both
modules, acting as the rotating shaft that transfers torque and ensures consistent winding behavior.
Internal Cord Routing
Lift cords wrap around the Cord Reel, then route through the bamboo slats and terminate at the bottom rail.
The Cord Bundle secures the cords and allows fine tension tuning to match shade size, weight, and travel.
In a true Cordless Spring Mechanism, cords remain internal—no external hanging loops are required.
How the Cordless Spring Mechanism Works
1) Fully Extended (Shade Down)
When the shade is fully lowered, most of the cord length is distributed through the bamboo slats, leaving fewer wraps
on the Cord Reel. The constant force spring inside the T1 Spring Box remains active,
continuously providing counterbalancing force to stabilize the system.
2) Lifting (Shade Up)
As the user pulls the bottom rail upward, the Fiber Glass Hexagonal Rod rotates. This rotation drives
the Cord Reel to take up cord length, increasing the number of wraps. Throughout travel, the
Cordless Spring Mechanism maintains a consistent feel because the constant force spring delivers
near-uniform output across the motion range.
3) Pull-and-Stop Control
A key experience advantage of the Cordless Spring Mechanism is its pull-and-stop behavior.
Users can stop at any height simply by releasing the bottom rail. The system’s force balance helps prevent drift,
rebound, or “creeping” when properly matched to the shade load.
Practical cue: As the shade moves, cord wraps on the Cord Reel decrease when lowering
and increase when lifting—while the Fiber Glass Hexagonal Rod synchronizes the rotation of the top modules.
Why a Constant Force Spring Improves the Cordless Spring Mechanism
The performance center of the T series Cordless Spring Mechanism is the constant force spring in the
T1 Spring Box. Compared with traditional spiral or torsion springs, constant force springs are preferred in position-holding lift architectures because they output a flatter force curve over travel.
Consistent Hand Feel Across Full Travel
With constant force behavior, lifting resistance stays more uniform from top to bottom. Users avoid the typical
“gets heavier at the end” sensation found in variable-torque spring designs.
Better Load Balance for Natural Bamboo Materials
Bamboo Roman shades can exhibit natural weight variation. A constant force spring helps compensate for uneven mass
distribution and reduces common issues such as tilt, skew, or uneven lifting.
Durability & Predictable Aging
A well-designed constant force spring can provide more predictable force retention over repeated cycles, improving
long-term stability and reducing service complaints—an important advantage for any premium Cordless Spring Mechanism.
Cordless Safety Advantages in Real Homes
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One of the clearest benefits of a Cordless Spring Mechanism is the removal of external hanging cords.
By keeping cords internal—routed through the bamboo slats—this architecture helps reduce the entanglement risks
associated with traditional corded systems for children and pets.
- No external pull cords for a cleaner, safer appearance
- Internal cord routing through bamboo slats only
- Safer user interaction via direct bottom-rail operation
System Components: Built to Work as One Cordless Spring Mechanism
T1 Spring Box
- Houses the constant force spring
- Provides stable lift assistance through travel
- Key driver of long-term feel consistency
Cord Reel
- Controls winding/unwinding of internal lift cords
- Maintains orderly wraps to reduce localized wear
- Wrap count increases when lifting and decreases when lowering
Fiber Glass Hexagonal Rod
- Acts as the torque transmission shaft between top modules
- Hexagonal profile improves anti-slip torque coupling
- High strength-to-weight ratio supports stable rotation
Cord Bundle
- Fixes cords at the bottom rail
- Enables tension adjustment to refine balance and alignment
- Improves installation repeatability for production builds
User Experience: Smooth, Quiet, and Intuitive
| T series loading capacity test（For reference：Maxium） | ||||||
| Test base on 96″ 2.4M | ||||||
| 2 cord reel without resistance | 2 cord reel with full resistance | adjustable incremental bearing capacity range | ||||
| Spring Spec. | Initiative Capacity/g | End Capacity/g | Initiative Capacity/g | End Capacity/g | Initially adjustable bearing capacity/g | End adjustable bearing capacity/g |
| 0.09-16-3000 | 720 | 320 | 1220 | 150 | 720~1200 | 320~150 |
| 0.10-16-3000 | 870 | 480 | 1550 | 200 | 870~1550 | 480~200 |
| 0.11-16-3000 | 1070 | 580 | 1820 | 270 | 1070~1820 | 580~270 |
| 0.12-16-3000 | 1270 | 780 | 2270 | 370 | 1270~2270 | 780~370 |
A properly tuned Cordless Spring Mechanism delivers a refined tactile experience:
smooth lifting, quiet operation, and predictable stopping behavior. Users simply pull the bottom rail to move the shade
and release to stop—no dangling cords, no extra steps.
- Pull-and-stop control at any height
- Consistent lifting resistance enabled by constant force behavior
- Cleaner aesthetics with no external cords
- Lower perceived noise due to controlled winding and balanced load
Applications & Customization
The T series Cordless Spring Mechanism is designed specifically for bamboo Roman shades and similar natural-fiber Roman shade constructions.
System matching can be optimized based on shade width, height, fabric/bamboo mass, and bottom-rail weight.
Typical Use Cases
- Bamboo Roman shades
- Natural-fiber Roman shades
- Premium residential projects requiring cordless safety architecture
- OEM/ODM production programs needing consistent assembly and tuning
FAQ: T1 Cordless Spring Mechanism
Does the T1 Cordless Spring Mechanism have any external pull cords?
No. In this Cordless Spring Mechanism, cords are routed through the bamboo slats. Users operate the shade by pulling the bottom rail.
What component enables pull-and-stop behavior?
The constant force spring inside the T1 Spring Box provides balanced lift assistance, enabling stable stopping at different heights when the system is properly matched to the shade load.
What is the purpose of the Cord Bundle?
The Cord Bundle secures cords at the bottom rail and allows fine adjustment of cord tension for alignment and consistent operation.
Why use a Fiber Glass Hexagonal Rod?
The Fiber Glass Hexagonal Rod provides stable torque transmission and anti-slip coupling between the top modules, helping maintain synchronized rotation during lifting and lowering.
Field Insight
The real value of a Cordless Spring Mechanism is not only removing cords—it is achieving
system-level force balance that feels stable in daily use.
- Constant force spring output defines whether the hand feel stays consistent across travel.
- Cord winding geometry influences smoothness, noise perception, and wear behavior.
- Tension calibration via Cord Bundle improves alignment, reduces skew, and increases build repeatability.
- Shaft coupling through a Fiber Glass Hexagonal Rod supports stable torque transfer and synchronized motion.
In short: the T series solution is a complete Cordless Spring Mechanism platform for bamboo Roman shades—engineered
to deliver safer operation, cleaner design, and more predictable long-term behavior.
