A governor rope and lever can actuate wedges that grip an elevator guide rail. Explore that mechanical chain and calculate the lateral advance of an ideal straight wedge guide from its lift and angle. These geometric results do not predict braking force, stopping distance or safety performance.
Ideal Wedge-Path Geometry Calculator
Enter a declared vertical lift, ideal guide angle and initial lateral gap. The worksheet resolves one right-triangle path only; it does not predict contact force, friction, deceleration, stopping distance, capacity or compliance.
Equation Used
- The guide path is an ideal straight line at declared angle alpha from vertical.
- Vertical lift y and initial lateral gap c are declared nonnegative dimensions.
- The trigonometric projection does not represent a particular safety gear or establish engagement.
- Housing compliance, wedge shape, rollers, springs, linkages, tolerances, contact, friction, load, speed, energy, rail response, braking and code compliance are excluded.
The schematic illustrates the governor rope, lever and wedge paths. The calculator separately resolves an ideal straight guide; its entered dimensions do not change the illustrative animation.
A stopped governor rope actuates car-mounted safety gear
EP Patent 1,663,837 describes the conventional chain: a governor rope travels with the elevator car, the overspeed governor locks, and the stopped rope activates safety gear mounted on the car. A safety lever then moves a wedge in its housing so the wedge grips the guide rail.
The animation keeps the governor sheave, rope, car lever, synchronizing member and paired wedge paths visibly connected. Phase shows a qualitative actuation sequence only; it is not elapsed time or stopping travel.
From governor motion to wedge actuation
Otis's published safety-chain overview likewise identifies flyweights in a governor and says an overspeed event initiates the machine brake and then the car safeties. Different products and jurisdictions implement and govern the chain differently.
This page does not select, install, adjust, test, inspect, reset or certify safety gear. Current applicable codes, manufacturer instructions and qualified elevator professionals control those tasks.
Ideal declared right-triangle projection
y is a declared vertical component, alpha is an ideal straight-guide angle from vertical, and c is a declared initial lateral gap. The results are distances along and across an ideal straight guide, without a contact or force model.
Declared geometry example
For y=20 mm, alpha=12 degrees and c=4 mm, ideal lateral advance is about 4.25 mm, guide-path length is about 20.45 mm, arithmetic remaining gap is 0.00 mm and arithmetic advance beyond the entered gap is about 0.25 mm.
That arithmetic does not establish physical contact, grip, force, braking or safe operation.
Limits of the ideal guide calculation
A real safety gear includes detailed wedge or roller profiles, housings, springs, linkages, rail interaction, materials, friction, deformation and governed test criteria. None can be inferred from this ideal triangle.
Geometric advance beyond the entered gap is simply the excess of x over c. It does not establish rail contact, clamping force, braking performance or a suitable adjustment for an actual safety gear.
Elevator safety-gear questions
Does the calculator predict stopping distance or deceleration?
No.
What initiates the illustrated conventional chain?
The cited patents describe an overspeed governor locking the governor rope, whose relative motion actuates car-mounted safety gear.
Does arithmetic advance beyond the entered gap prove rail contact?
No.
Does the animation show real timing or travel?
No.
Can this page guide elevator testing or maintenance?
No.
Elevator safety-gear references
- EP Patent 1,663,837, Elevator safety gear arrangement: conventional governor-rope chain, car-mounted safety lever and wedge gripping a guide rail.
- US Patent 5,096,020, Elevator safety apparatus: paired wedge housings around a guide rail and lever-driven wedge movement.
- Otis, The Elevator Safety Chain: manufacturer overview of governor flyweights, machine-brake initiation and car safeties.
- ASME A17.1/CSA B44-2022 table of contents: confirms that current elevator codes separately govern governors, car safeties and guide rails; this page does not reproduce requirements.
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