Push-button switch units

A push-button unit comprising, in combination, a sleeve member having a longitudinal axis;

• a push-rod member mounted to be axially displaceable in said sleeve member between an outer position and an inner position;
• a guide groove system defined in a surface portion of said push-rod member;
• a latching element mounted on said sleeve member to extend internally thereof, said guide groove system being engageable by a portion of said latching element, responsive to said push rod being displaced to said inner position, thereby to latchably retain said push-rod in said inner position and, responsive to renewed pressure being applied to said push-rod, to allow said push-rod to return to said outer position;
• an opening provided in said sleeve member in the vicinity of said latching element to provide access thereto;
• a recess defined in said surface portion of said push-rod member;
• and a rib member defined in said surface portion of said push-rod member and extending between said recess and said guide groove system;
• said push-rod surface portion and the inner surface of said sleeve defining a free intermediate space for lateral displacement of said latching element portion;
• whereby said latching element is selectable positionable on either side of said rib member, by a tool inserted through said opening, to cause said latching element portion to enter a selected one of said guide groove system and said recess;
• whereby, in dependence on the selected setting of said latching element said push-button unit is ready for operation selectively with latching action and without latching action without any disassembly of the components of the unit or displacement of any such components except said latching element.