Manually-actuated hydraulic shutoff valve

Abstract

A shutoff valve includes a valve housing with inlet and outlet openings and a hole drilled in alignment with the inlet (or outlet) opening. A pusher is slidably positioned in the hole for extension toward the inlet opening, the pusher including a shutoff member inside the hollow housing adapted to close off the inlet opening when extended to a inlet-closed position, and to open the inlet opening when retracted to an inlet-opened position. The pusher includes a handle for manually pressing the pusher and shutoff member toward the inlet opening. A spring biases the pusher toward the inlet-opened position. By this arrangement, the pusher is manually closed but cannot accidentally be left in the inlet-closed position due to being biased toward the inlet-opened position.

1 . A shutoff valve comprising:
 a valve housing including inlet and outlet openings and a hole drilled in alignment with one of the openings; and   a pusher slidably positioned in the hole for extension toward the one opening, the pusher including a shutoff member inside the hollow housing adapted to close off the one opening when extended to a closed position, and to open the one opening when retracted to an opened position, the pusher including a handle for manually pressing the pusher and shutoff member toward the one opening, and including a spring for biasing the pusher toward the opened position; whereby the pusher is manually closed but cannot accidentally be left in the closed position due to being biased toward the opened position.   
     
     
         2 . The valve defined in  claim 1 , wherein the pusher includes a rod, and including a retainer screw attaching the washer to an end of the rod. 
     
     
         3 . The valve defined in  claim 2 , wherein the washer is metal. 
     
     
         4 . The valve defined in  claim 3 , wherein the washer is configured and adapted to abut an end of a hose fitting engaging the housing to close the one opening and thus prevent oil flow through the housing. 
     
     
         5 . The valve defined in  claim 4 , wherein the washer does not include a resilient seal member. 
     
     
         6 . The valve defined in  claim 1 , wherein the pusher includes a rod slidably engaging the housing, and wherein the handle includes a flat button on an exterior end of the rod. 
     
     
         7 . The valve defined in  claim 1 , wherein the pusher includes a rod slidably engaging the housing, and a spring that biases the rod away from a closed position. 
     
     
         8 . A hydraulic system including an oil reservoir, a hydrostat drive, an oil filter, and lines operably connecting same, and further including the valve defined in  claim 1  that is operably connected to one of the lines between the reservoir and the drive. 
     
     
         9 . The valve defined in  claim 8 , wherein the valve is in one of the lines adjacent the filter. 
     
     
         10 . A shutoff valve comprising:
 a valve housing including inlet and outlet openings and a passageway therebetween, and including a hole drilled in the housing to the passageway; and   a pusher slidably engaging the hole for extension toward the passageway, the pusher including a shutoff member inside the hollow housing shaped to close off the passageway and a spring-bias return to bias the shutoff member away from the passageway, the pusher characteristically being made of hard material and not including a resilient member for sealing the passageway; whereby the pusher is manually closed but cannot accidentally be left in the closed position due to being biased toward the opened position.   
     
     
         11 . The shutoff valve defined in  claim 10 , wherein the shutoff member is made entirely of metal. 
     
     
         12 . The shutoff valve defined in  claim 10 , wherein the shutoff member and housing do not include a resilient seal. 
     
     
         13 . A method comprising steps of:
 providing a valve housing including inlet and outlet openings and a hole drilled in alignment with one of the openings;   providing a pusher slidably positioned in the hole for extension toward the one opening, the pusher including a shutoff member inside the hollow housing adapted to close off the one opening when extended to a closed position, and to open the one opening when retracted to an opened position;   manually pressing the pusher and shutoff member toward the one opening against a spring bias on the pusher to close oil flow through the one opening; and   releasing the pusher so that the spring biases the pusher toward the opened position; whereby the pusher is manually closed but cannot accidentally be left in the closed position due to being biased toward the opened position.   
     
     
         14 . The method defined in  claim 13 , wherein the step of manually pressing the pusher to close oil flow includes metal on metal contact between the shutoff member and the housing, and does not include sealing the one opening with a resilient member.