Sheet glass core drilling machine

Claim 2

Apparatus for driving a drilling tool through an operating cycle of reciprocating travel including an interval of drilling into a sheet of glass or glass-like material, comprising: a fluid cylinder, a piston in said fluid cylinder operatively connected to said drilling tool, fluid pressure means operatively connected to said fluid cylinder to extend said drilling tool at a constant feed rate interval of fast travel up to a position close to the surface of said sheet and a constant feed rate interval of slow travel from engagement of said drilling tool with the surface of said sheet to a predetermined depth of cut into said sheet, and adjustable timing means operatively connected to said fluid pressure means for controlling the duration of said constant feed rate time intervals whereby to control the positions of said drilling tool at the initiation and termination of said slow extension time interval to control the depth of cut into said sheet.

Claim 3

Apparatus as defined in claim 1 wherein said fluid pressure means includes a first flow restricter and a second flow restricter and valve means for selectively connecting only one of said restricters in flow restricting relation to said drive cylinder to control fluid flow rate and provide said fast travel and for selectively connecting both of said restricters in flow restricting relation to said drive cylinder to control fluid flow rate and provide said slow travel.

Claim 4

Apparatus as defined in claim 2 wherein said valve means comprises two solenoid-operated valves.

Claim 5

Apparatus as defined in claim 3 wherein said solenoids are energized by said timing means.

Claim 6

Apparatus as defined in claim 1 wherein said adjustable timing means comprises two electronic timers.

Claim 7

Apparatus as defined in claim 5 wherein said timers have digital read-out.

Claim 8

Apparatus for drilling holes in a sheet of glass or glass-like material with a pair of opposed cooperating coaxial drilling tools located on opposite sides of the sheet and adapted to be fed alternatingly into said sheet about one-half the depth thereof comprising: means for driving said tools through alternating operating cycles of reciprocating travel, each cycle including an interval of drilling into said sheet, said means including for each drilling tool; a fluid cylinder, a piston in said fluid cylinder operatively connected to said drilling tool, fluid control means operatively connected to said fluid cylinder to extend said drilling tool at a constant feed rate time interval of fast travel up to a position close to the surface of said sheet and a constant feed rate time interval of slow travel from engagement of said drilling tool with the surface of said sheet to a predetermined depth of cut into said sheet, and adjustable timing means operatively connected to said fluid control means for controlling the duration of said constant feed rate time intervals whereby to control the positions of said drilling tool at the initiation and termination of said slow extension time interval to control the depth of cut into said sheet.

Claim 9

Apparatus for drilling holes in a sheet of glass or glass-like material with a pair of opposed cooperating coaxial drilling tools located on opposite sides of the sheet and adapted to be fed alternatingly into said sheet about one-half the depth thereof comprising: means for driving said tools through alternating operating cycles of reciprocating travel, each cycle including an interval of drilling into said sheet, said means including for each drilling tool; a fluid cylinder, a piston in said fluid cylinder operatively connected to said drilling tool, fluid control means operatively connected to said fluid cylinder to extend said drilling tool at a constant feed rate time interval of fast travel up to a position close to the surface of said sheet and a constant feed rate time interval of slow travel from engagement of said drilling tool with the surface of said sheet to a predetermined depth of cut into said sheet, and adjustable timing means operatively connected to said fluid control means for controlling the duration of said constant feed rate time intervals whereby to control the positions of said drilling tool at the initiation and termination of said slow extension time interval to control the depth of cut into said sheet.

Claim 10

Apparatus as defined in claim 7 wherein the axis of said drilling tool is vertical and wherein said tools comprise an upper drilling tool and a lower drilling tool.

Claim 11

Apparatus as defined in claim 8 including means for clamping said glass sheet in a horizontal position interposed between said tools, said means comprising a horizontal table, a clamping jaw located above said table and movable toward and away from said table, and fluid pressure means operatively associated with said clamping jaw for moving said jaw and applying gripping pressure to said glass sheet.

Claim 12

Apparatus as defined in claim 9 wherein said fluid pressure means includes control means for applying a relatively high clamping during the drilling operation of said lower drilling tool and a relatively low clamping pressure during the drilling operation of said upper drilling tool.