Block holder for ophthalmic lens blanks

Claim 2

In a blocking apparatus wherein a preformed cylindrical block is joined to a lens blank in predetermined relationship to the prescribed optical and geometrical properties of the finished lens, said apparatus comprising: a frame having means for supporting the lens blank; a circular ring for surrounding said block and having means for retaining said block therein, said ring having a spherical segment associated therewith; means fixedly mounted on said frame for laterally supporting said ring immediately above said lens blank, said lateral support means being in engagement with said spherical segment for cooperating in accurately positioning said ring when tilted into engagement with the convex surface of said lens blank; and means for adjusting the relative rotational positioning between said block and said frame when said block is retained in said ring.

Claim 3

The blocking apparatus as defined in claim 1 1 wherein said means for adjusting the relative rotational positioning comprises integrating means between said circular ring and said block whereby relative rotation therebetween is precluded.

Claim 4

The blocking apparatus as defined in claim 2 wherein the said means for retaining said block within said ring comprises a frictional engagement between the outer periphery of said block and at least a portion of the internal diameter of said ring.

Claim 5

The blocking apparatus as defined in claim 3 wherein said ring further includes a cylindrical gasket having a downwardly extending locating edge adaptEd to engage the lens blank when said ring is positioned in said lateral support means.

Claim 6

The blocking apparatus as defined in claim 4 further including indicia on said lateral support means to indicate the relative rotational position of said ring.

Claim 7

The blocking apparatus as defined in claim 1 further including means for accurately positioning said lens blank on said supporting means in a predetermined relationship with respect to said lateral support means.

Claim 8

The blocking apparatus as defined in claim 6 wherein said lateral support means comprises a centering member defining a cylindrical opening, said cylindrical opening having a diameter substantially the same as the outer diameter of said ring such that said centering member rotatably encloses said ring.

Claim 9

Blocking apparatus for joining a performed lens block to a lens blank in predetermined relationship to the prescribed optical and geometrical properties of the finished lens, said blocking apparatus comprising: a frame having means for supporting a lens blank; a lens block to which said lens blank is to be joined; a circular ring for supporting said lens block, said circular ring including means for frictionally retaining said block therein; a centering member fixedly mounted to said frame for laterally supporting said circular ring immediately above said lens blank, said centering member defining a cylindrical opening having a diameter substantially the same as the outer diameter of said circular ring for rotatably enclosing said circular ring; and means for adjusting the relative rotational positioning between said circular ring together with said lens block and said centering member when said lens block is retained in said circular ring.

Claim 10

Blocking apparatus for joining a performed lens block to a lens blank in predetermined relationship to the prescribed optical and geometrical properties of the finished lens, said blocking apparatus comprising: a frame having means for supporting a lens blank; a lens block to which said lens blank is to be joined; a circular ring for supporting said lens block, said circular ring including means for frictionally retaining said block therein; a centering member fixedly mounted to said frame for laterally supporting said circular ring immediately above said lens blank, said centering member defining a cylindrical opening having a diameter substantially the same as the outer diameter of said circular ring for rotatably enclosing said circular ring; and means for adjusting the relative rotational positioning between said circular ring together with said lens block and said centering member when said lens block is retained in said circular ring.

Claim 11

Blocking apparatus as defined in claim 8 wherein said means for adjusting the relative rotational positioning comprises interengaging means between said circular ring and said block for precluding relative rotation therebetween.

Claim 12

Blocking apparatus as defined in claim 9 wherein said centering member includes indicia for indicating the relative rotational positioning between said ring together with said lens block and said centering member.