Abstract: A gate opening device for shifting a gate from a closed position to an open position on loss of power to a motive device includes a housing, the motive device carried by the housing, and a drive shaft coupled to and rotatable by the motive device. A drive member is coupled to the drive shaft and capable of being connected to a gate for causing shifting movement thereof. A base plate is coupled to the drive shaft and a drive plate is coupled to the drive member and pivotally coupled to the base plate. A shear pin engages the drive plate and the base plate, preventing relative pivoting thereof. The shear pin is formed of a material which allows a shearing effect on a specified torque or force, causing the shear pin to break or shear and allow relative pivotal movement of the drive plate and the base plate.

Abstract: An apparatus for shifting a gate from a closed position to an open position on emergency from loss of power to a motive means. The apparatus generally comprises a housing along with a motive means, such as an electric motor, operatively associated with the housing. A drive member is operatively connected to the motive means and is capable of being connected to a gate for causing rotating movement of the gate. Typically the drive member is connected to the motive means by means of a drive shaft, which extends from the housing. The apparatus comprises a manually operable release member, which is operatively connected to a drive plate. The release member functions as part of an override means and is capable of being sheared on application of force, thereby releasing the drive plate from a base plate of the motive means operatively disconnecting the drive member from the motive means, and more particularly disconnecting the drive member from the drive shaft.