Method for the manufacture of flexible disks

Claim 2

In a method for the manufacture of flexible disks engraved on at least one side by means of a compression press having a fixed plate and a moving plate, a first engraved mold being carried by one of said plates and a second engraved mold or counter-mold being carried by the other of said plates, the improvement comprising the steps of: bringing a strip of material between said plates of said compression press with said plates being open; making a preliminary hole in the strip by means of a punch carried by the moving plate during the closing of said plates; matching said punch to a second hollow punch carried by the other of said plates with said punches serving as centering means for the molds carried by said plates and one of said punches floating in the corresponding plate in such a way that the molds are centered with respect to one another at the end of the closing phase due to the engagement of said first punch in said second punch; and cutting a central hole in the strip by means of said second punch with said second punch being maintained in the end of its travel position throughout the end of the pressing cycle.

Claim 3

The method according to claim 1, wherein the step of pressing is performed in the hot state and wherein said punching of said central hole is carried out at a temperature chosen in such a way that the shear stress is as low as possible.

Claim 4

In a method for the manufacture of flexible disks engraved on at least one side by means of a compression press having a fixed plate and a moving plate between which is advanced in step-wise manner a strip of material to be pressed, a first engraved mold being carried by one of said plates and a second engraved mold or counter-mold being carried by the other of said plates, the improvement comprising the steps of; perforating said strip during the moving together of said two plates by means of a punch of diameter d 1 having a base of diameter d 2 which is greater than the diameter d 1 ; forming a centering means for the corresponding mold and sliding in a sleeve provided for this purpose in a moving plate, with d 1 being the diameter of a preliminary hole and d 2 being the diameter of a central hole to be cut into said strip; centering of the two molds during the end of the closing phase; guiding said punch of diameter d 1 in a second punch of d 2 and sliding in a sleeve provided for this purpose in said other of said plates and used as a centering means for the corresponding mold; perforating said second punch by a funnel-shaped hole whose bottom of diameter d 1 is adjusted to the first punch, the sleeve located in the upper plate being movable in said plate in order to permit centering with the centering means and the second punch gripping the strip of material when said plates are closed; pressing and perforating said central hole by means of said second punch having a sufficient force applied in order to shear the material with respect to said mold carried by said moving plate with said second punch being maintained in the working position throughout the end of the pressing cycle.

Claim 5

In a method for the manufacture of flexible disks engraved on at least one side by means of a compression press having a fixed plate and a moving plate between which is advanced in step-wise manner a strip of material to be pressed, a first engraved mold being carried by one of said plates and a second engraved mold or counter-mold being carried by the other of said plates, the improvement comprising the steps of; perforating said strip during the moving together of said two plates by means of a punch of diameter d 1 having a base of diameter d 2 which is greater than the diameter d 1 ; forming a centering means for the corresponding mold and sliding in a sleeve provided for this purpose in a moving plate, with d 1 being the diameter of a preliminary hole and d 2 being the diameter of a central hole to be cut into said strip; centering of the two molds during the end of the closing phase; guiding said punch of diameter d 1 in a second punch of d 2 and sliding in a sleeve provided for this purpose in said other of said plates and used as a centering means for the corresponding mold; perforating said second punch by a funnel-shaped hole whose bottom of diameter d 1 is adjusted to the first punch, the sleeve located in the upper plate being movable in said plate in order to permit centering with the centering means and the second punch gripping the strip of material when said plates are closed; pressing and perforating said central hole by means of said second punch having a sufficient force applied in order to shear the material with respect to said mold carried by said moving plate with said second punch being maintained in the working position throughout the end of the pressing cycle.

Claim 6

A method according to claim 1 or 3 comprising the further steps of; opening said moving plate at the end of the pressing cycle; and bringing said second punch level with the mold carried by the corresponding plate in such a way as to facilitate demolding.

Claim 7

A method according to claim 4 comprising the further step of; ejecting the shaving resulting from the punching of said central hole by said second punch by means of ejectors sliding between said first punch and the centering means associated therewith.