US 12,024,402 B2 · Stairlift overspeed safety system

Abstract

Systems, apparatuses, and methods are described for a stairlift overspeed safety system are disclosed. The overspeed safety system may include a centripetal cam assembly, a trigger assembly, and a jammer assembly. The centripetal cam assembly may include a spring-loaded plate and a plurality of centripetal cams connected to the spring-loaded plate, configured to move to an extended position when the rail speed exceeds the speed threshold. The trigger assembly may include a trigger plate configured to be pushed by at least one of the centripetal cams when moved to the extended position. Pushing the trigger plate may cause a switch to open to shut off power to the motorized stairlift. The jammer assembly may include a jammer configured to wedge between teeth of a rack and pinion of the motorized stairlift to initiate a deceleration to stop movement of the motorized stairlift.

Claims18

Dependent claims

A motorized stairlift comprising:

a stairlift rail including rail sections that, when installed, are arranged at different angles to a horizontal plane;
a carriage mounted on the stairlift rail for movement along the stairlift rail by a rack and pinion system;
a motor configured to power movement of the carriage along the stairlift rail through the rack and pinion system;
and
an overspeed apparatus configured to shut off the motor and to stop movement of the carriage along the stairlift rail when a speed of the stairlift rail exceeds a speed threshold, wherein the overspeed apparatus comprises:
a jammer assembly comprising a jammer configured to be released upon the speed of the stairlift rail exceeding a speed threshold, wherein releasing the jammer causes the jammer to wedge between teeth of the rack in the rack and pinion system to initiate a deceleration to stop movement of the motorized stairlift.

3 more elements

An overspeed safety apparatus for a motorized stairlift, the overspeed safety apparatus comprising:

a centripetal cam assembly comprising plurality of centripetal cams linked together and configured to hold the plurality of centripetal cams in a collapsed position when the stairlift operates at a rail speed below a speed threshold and wherein the plurality of centripetal cams are configured to move to an extended position when the rail speed exceeds the speed threshold;
a trigger assembly operably connected to the centripetal cam assembly, and configured to be impacted by at least one of the plurality of centripetal cams, when the plurality of centripetal cams move to the extended position, so as to cause a switch to open to shut off motor power to the motorized stairlift;
and
a jammer assembly operably connected to the trigger assembly and comprising a jammer;
wherein the jammer is formed of a plastic material shaped progressively thicker from a first end to a second end;
wherein trigger assembly comprises a trigger plate, and wherein at least one of the plurality of centripetal cams, when moved to the extended position, is configured to push the trigger plate to open the switch;
and
wherein the plurality of centripetal cams comprises four centripetal cams radially spaced around a spring-loaded linkage plate.

5 more elements

Dependencies are inferred from the claim text.

Stairlift overspeed safety system

Life of this patent

Stairlift overspeed safety system

Life of this patent

Abstract

Claims18