Electric toe sensors are most commonly used on a lift table that is installed in a pre-formed pit.
The toe sensors consist of a 4 sided steel bar assembly that is suspended by chains just below the underside of the lift table platform. The toe sensor is equipped with 4 electric limit switches that are wired in series in the closed position.
To lower the platform the operator depresses the control station down button. The electric signal travels from the down button through the 4 closed circuit limit switches to the lowering valve that is located on the power unit.
The electric signal activates the lowering valve and the hydraulic fluid in the extended cylinder(s) now flows from the cylinder(s) back through the open lowering valve to the reservoir causing the cylinders to retract and the lift platform to lower.
During platform lowering if any object such as the operators foot comes in contact and causes the suspended 4 sided steel toe sensor bar assembly to raise slightly the lowering stops.  The toe sensor stopping the platform from lowering has addressed a potential pinch/shear point between the underside of the lowering platform and the operator’s feet/toes as the platform lowers into the pit.
The lowering stops because by raising the steel bar assembly slightly one or more of the electric limit switches has switched to open circuited interrupting the electric signal from the down button that activates the lowering valve.
Please refer to page 5 in this link to view a toe sensor. https://www.pentalift.com/wp-content/uploads/2020/10/ProSeries.pdf
When the obstacle is removed the sensor bar lowers and returns to its normal position. The operator can now depress the down button and the platform will once again continue to lower.
For additional information on any Pentalift product please contact the Pentalift Sales Department.