Device at hydraulic motor

A hydraulic motor device comprising in combination:

• a. a cylinder having an upper end and a lower end,
• b. a piston mounted for reciprocating movement away from and toward the upper end of said cylinder,
• c. a spring means positioned between the lower end of said cylinder and the piston and serving to bias said piston toward the upper end of said cylinder,
• d. a source of fluid pressure for moving said piston toward the lower end of said cylinder,
• e. a fluid inlet adjacent the upper end of said cylinder and a fluid outlet adjacent the lower end of said cylinder,
• f. an overflow aperture extending from one side of the piston to the other,
• g. a stop valve,
• h. resilient mounting means on said piston for mounting said stop valve with respect to said overflow aperture so that the stop valve can only alternate between a first completely closed position and a second completely open position,
• i. a swing lever projecting outwardly from said piston toward the lower end of the cylinder,
• j. a spring loaded rocker arm mounted adjacent the lower end of said cylinder,
• k. said swing lever being mounted so that as the piston moves downwardly toward the lower end of the cylinder the swing lever will first compress said spring loaded rocker arm and then release it,
• whereby when said spring loaded rocker arm is released it will impact against said stop valve and move it to the completely open position and said stop valve will not close until said spring means causes said stop valve to impact against the upper end of said piston.