Reversing mechanism for a switchover seat-type valve

A switchover valve for hydraulic control, comprising:

• a valve housing formed with a plurality of ports and annular seats between said ports;
• an elongated hollow valve piston axially shiftable in said housing between opposite positions in which said piston respectively engages said seats to switchover flow through said ports;
• a pair of levers pivotally connected to an end of said hollow valve piston;
• respective abutment brackets affixed to said housing at locations angularly offset about an axis of said hollow valve piston by about 180.degree., traversed by the respective lever and each formed with two axially spaced stops engageable by said levers;
• a shifting member extending generally perpendicularly to said axis and spaced from said end;
• means articulatingly connecting ends of said levers remote from said hollow valve piston to said shifting member for displacing said ends of said levers from positions in which said levers engage respective ones of said stops past deadcenter positions into positions in which said levers engage the other ones of said stops;
• spring means biasing said ends of said levers toward one another;
• a control rod traversing said shifting member axially and connected with a working piston for effecting the switchover of flow;
• and
• respective entrainers spaced apart on said rod and respectively engageable with opposite outer surfaces of said shifting member selectively upon axial displacement of said control rod for entraining the shifting member in the corresponding direction of axial displacement, thereby displacing said levers through said deadcenter positions and effecting shifting of said hollow valve piston in the opposite axial direction to switchover the flow.