Braille printing solenoid housing

Abstract

Disclosed is a printing solenoid specifically adapted and improved for the printing of Braille dots and in particular interpoint Braille. A plunger and printing shaft are fixably mounted together and the combination mounted for slidable movement in a rear end cap and in a molded insert bearing between energized and deenergized positions. The plunger/printing shaft combination are located within a bobbin having an electric coil wound thereon. A tubular case encloses the coil and mounts a front bushing which in turn mounts the molded insert bearing. A rear flux washer is held in place between the bobbin by the rear end cap which is retained within the rear portion of the tubular case. During energization, the plunger and printing shaft combination move such that the shaft strikes a piece of paper to be imprinted with a Braille dot. Depending upon whether the dot is to extend away from the solenoid or towards the solenoid, an embossing ball or an embossing recess is used on the end of the printing shaft. An internal return spring moves the plunger/printing shaft combination back to its deenergized position. A high degree of printing accuracy is achieved by slidably mounting the plunger/printing shaft combination in bearings which are separate from the bobbin coil assembly. The end cap is responsive to a torque applying device, and through the rear flux washer and the bobbin, torque can be applied to the bushing to aid in inserting or removing the solenoid from a dense solenoid array.