Brake apparatus for a hydraulic elevator

A brake apparatus for locking a load carrying piston in a hydraulic elevator comprising:

• at least one brake arm pivotally mounted at a pivot point adjacent a generally cylindrical piston of a hydraulic elevator;
• a brake lining body attached to said brake arm and having an inwardly facing surface for engaging a surface of the piston and a lower edge, said inwardly facing surface including a piston surface contact portion and an adjacent recessed portion extending to said lower edge;
• and
• a shoulder formed on said brake lining providing a transition between said piston surface contact portion of said inwardly facing surface and said recessed portion of said inwardly facing surface, a central portion of said shoulder being positioned generally in a same horizontal plane with said pivot point;
• whereby as said brake arm is pivoted about said pivot point to move said lower edge toward the piston, said recessed portion clears the surface of the piston and said central portion of said shoulder initially engages the surface of the piston thereby minimizing forces applied to the surface of the piston and the pivot point through said brake arm.

A brake apparatus for engaging and locking a load carrying piston of a hydraulic elevator comprising:

• a beam mounted at an upper end of a hydraulic cylinder;
• a pair of opposed brake arms pivotally mounted at respective pivot points on said beam adjacent a piston extending from said hydraulic cylinder;
• a brake lining attached to each said brake arm, each said brake lining having a body with an inwardly facing surface shaped for engaging a surface of the piston and a lower edge, said inwardly facing surface including a piston surface contact portion adjacent a recessed portion extending to said lower edge;
• at least one shoulder formed on each said inwardly facing surface providing a transition between said piston surface contact portion of said inwardly facing surface above said shoulder and said recessed portion of said inwardly facing surface below said shoulder, said shoulder having a generally horizontally extending central portion and extending therefrom at a slight upward incline to opposite side edges of said brake lining body, said central portion being positioned in a generally horizontally extending plane with said respective pivot point;
• and
• at least one oil carrying groove formed in said piston surface contact portion extending to one of said side edges;
• whereby as said brake arms are pivoted about said pivot points to move said lower edges toward the piston, said recessed portions clear the surface of the piston and said central portion of each said shoulder initially engages the surface of the piston thereby minimizing forces applied to the piston surface and said pivot points through said brake arms.