Ice-skate sharpener

Claim 1

In an ice-skate sharpening machine including a frame, a grinding wheel rotatable about a rotation axis, a motor to rotate said wheel, a diamond bit for dressing said wheel, an arm pivoted to said frame about a pivot axis perpendicular to said rotation axis and carrying said bit in a position facing the peripheral face of said grinding wheel, so arranged that pivoting of said arm back and forth will dress said grinding wheel peripheral face along an arc of a circle lying in a plane containing said rotation axis, the improvement consisting in an ice-skate clamp comprising a bracket, a pair of jaws each pivoted on said bracket about a jaw pivotal axis lying in a plane perpendicular to said rotation axis and each having a straight jaw face for engaging an ice-skate blade, means to close and open said jaws and retain the same in adjusted pivotal position, so that said jaw clamping faces are always equally distant on each side of a datum plane perpendicular to said rotation axis and passing through said pivotal axis of said arm, means to adjust and set the position of said bracket in a direction parallel to the rotation axis of said grinding wheel, means supporting said bracket for universal movement in said datum plane, said jaws each having a U-shape to encircle an ice-skate, said ice-skate blade contacting jaw faces being located at the free edge of one leg of said U-shaped jaws, while said pivotal connection is located at the free edge of the other leg of said U-shaped jaws, and wherein said means to close and open said jaws include an extension for each jaw projecting away from the ice-skate blade contacting faces relative to said jaw pivotal axis, a threaded bushing carried by the outer end of each extension, said bracket having a leg extending between said jaw extensions, an adjusting screw having an intermediate portion rotatably mounted in the outer end of said bracket leg, means to prevent axial movement of said screw relative to said bracket leg, said screw having threads of opposite pitch on each side of said central portion respectively engaging the threaded bushing of the jaw extensions whereby rotation of said screw in one direction will open said jaws equally away from said datum plane and rotation of said screw in the opposite direction will close said jaws equally towards said datum plane.