What Are Locking Gas Springs and How Do They Work?
Locking gas springs provide the ability to halt and secure a mobile component, such as an access hatch or machine guard, at any point throughout its full range of movement. Unlike standard gas struts that offer constant push-out force, these units incorporate a internal valve that, when closed, traps fluid or gas to prevent further travel.
⚡ In a Rush? Key Takeaways
- Locking struts provide infinite position control across 100% of the stroke length.
- Rigid locking springs prevent all movement, while elastic locks allow minimal ‘springy’ travel.
- Standard cycle life for high-quality industrial locking units exceeds 50,000 actuations.
- Always match the Newton force rating to the specific load and pivot geometry.
What is the Difference Between Rigid and Elastic Locking?
Rigid locking springs use internal fluid chambers to prevent all movement, while elastic springs allow slight motion due to nitrogen compressibility.
How Does Rigid Locking Perform Under Load?
Rigid locking uses hydraulic fluid separation to stop all piston travel, providing a static, unyielding position under high static loads.
In a rigid locking configuration, the piston cylinder contains both gas and hydraulic oil. When the release valve is closed, the oil cannot flow, creating a hydraulic lock that resists compression and extension forces equally.
- Ideal for medical beds and heavy machinery guards.
- Prevents “bounce” or drift under changing operator weight.
- Requires precise release valve alignment during installation.
Why Choose Elastic Locking for Your Application?
Elastic locking relies on compressed gas to hold position, allowing a small degree of movement similar to a standard car suspension unit.
Elastic locking struts are preferred when you need the load to have some “give.” Because they rely on gas compression rather than incompressible fluid, they act as a shock absorber while the valve is closed.
| Feature | Rigid Lock | Elastic Lock |
|---|---|---|
| Primary Medium | Hydraulic Oil | Nitrogen Gas |
| Movement Under Load | Zero | Minimal/Springy |
| Best Use | Static Weight Support | Dynamic/Shock Sensitive |
How Do I Operate a Locking Gas Spring?
Locking gas springs operate using a release pin or lever that must be depressed to allow the internal valve to move and the rod to travel.
What Methods Are Available for Remote Actuation?
Remote actuation uses mechanical cable assemblies or hydraulic push-buttons to trigger the release pin from a distance away from the strut.
Managing the release mechanism is the most critical design factor for equipment layout. Most manufacturers provide compatible cable-pull systems that allow for one-handed operation of heavy lids.
- Mechanical bowden cable release.
- Push-button handle integration.
- Direct-actuation lever arm.
Are There Safety Requirements for Release Buttons?
Safety standards dictate that release buttons must be guarded to prevent accidental operation, especially on heavy-duty industrial hatches.
On high-mass applications, an accidental release could cause the load to fall rapidly. I always recommend shrouded buttons to prevent impact-induced activation. Always refer to our complete measuring guide to ensure your linkage geometry remains within the manufacturer’s specified stroke limits.
Understanding Over-Extension and Mounting Orientation
Proper orientation is vital for internal valve performance; most locking gas springs must be mounted with the rod end facing downwards to ensure constant contact between the fluid and the valve seat.
If a locking strut is mounted rod-up, air bubbles can become trapped at the valve seat. This leads to “spongy” locking performance, where the strut drifts slightly even when locked, regardless of whether you are using a rigid or elastic model. If your design requirements dictate a rod-up orientation, you must specify a unit designed with a internal oil-flow tube or a gas-oil separation baffle to maintain consistent sealing.
Additionally, avoid “bottoming out” or “topping out” the strut. If the rod reaches the physical end of its stroke under load, the force generated can damage the internal valve seals. Always allow for 5–10mm of clearance at both ends of the stroke to protect the internal locking mechanism from mechanical fatigue.
Maintenance and Lubrication Guidelines
Locking gas springs are generally maintenance‑free, but periodic inspection and proper lubrication of external moving parts extend service life.
Although the internal valve and gas/oil chambers are sealed, the release pin, cable or lever mechanism can benefit from light grease to prevent corrosion and ensure smooth actuation. In harsh environments (dust, moisture, chemicals) consider using stainless‑steel hardware and protective boots.
Inspect the strut every 6–12 months for signs of oil leakage, valve wear, or loose mounting bolts. Replace the unit if the locking force drops or the release mechanism sticks.
Frequently Asked Questions About Locking Struts
Can I Field-Adjust the Locking Force?
Locking force is fixed at the point of manufacture and cannot be field-adjusted; the internal valve is only a binary on-off mechanism.
What Happens If the Release Mechanism Fails?
If the release mechanism fails, the strut defaults to the locked position, keeping the application safe but immobile until manually repaired.
Is a Locking Strut a Direct Replacement for Standard?
Locking struts have larger barrel diameters to accommodate valve hardware and are not direct replacements for standard gas springs.
If you are upgrading an existing assembly, check the mounting clearance carefully. You may need to review our end-fittings guide to ensure your existing brackets accommodate the added bulk of the locking assembly.
