In the majority of dock lift applications the dock lift is designed to be stored in the fully lowered position. Â However there are applications that require the docks lifts platform to remain stored in the raised position for an extended period of time.
An example of a dock lift application that requires the platform to remain stored in the raised position for an extended period of time is a dock lift that is installed into a 3 sided pit.
This link leads to drawings of dock lifts in many different types of installations. Drawing B illustrates a dock lift that is installed into a 3 sided pit. https://www.pentalift.com/wp-content/uploads/2021/04/Dock-Lift-Pit-Installation-Configurations-A-B-C-D-E.pdf
A 3 sided pit has 2 side walls and a back wall, the front of the pit is open. The top floor of the 3 sided pit is typically 48” above exterior grade, the dock lift is used to service from grade level or from any height of incoming truck bed to the finished floor height. The dock lift hydraulic system valves have a very slow leak rate. However over extended periods of time it is possible to for the dock lift platform to drift lower.  To secure the building and to prevent the possibility of a trip hazard or falling into the pit when not in use the dock lift platform is to remain in the raised position level with the surrounding floor surface for an extended period of time.
To prevent the dock lift platform from drifting down over extended periods of time the dock lift platform is equipped with 4 “swing out” night stops, one per corner of the platform. When not in use the swing out night stops are positioned “in line” with the dock lift platform and do not impede the raising and lowering operation of the dock lift.
This link leads to swing out night stops https://www.pentalift.com/solutions/dock-lift-night-locks/
To store the dock lift platform in the raised position the platform is first raised 1” – 2” above the finished floor level. The dock attendant then manually swings the 4 platform installed night stops outward 90 degrees, the platform is then lowered and the extended night stops rest on top of the floor keeping the dock lift platform level with the finished floor level.
The dock lift platform is now mechanically locked in the elevated position and can be left for an extended period of time with the dock lift platform level with the surrounding floor surface. Swing out night stops are not intended to mechanically lock a dock lift with a load on the platform in the raised position; they are designed to lock a dock lift with no load on the platform in the raised position only.
When the dock attendant is ready to use the dock lift they activate the control station up button and raise the dock lift 1” – 2” above the finished floor level. The dock attendant then manually swings/returns the 4 night stops back into line with the dock lift platform. With the night stops disengaged and re-positioned in line with the dock lift platform the dock lift is now ready to resume normal operations.
For additional information on any Pentalift product please contact the Pentalift Sales Department.