Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/02—Perforating by punching, e.g. with relatively-reciprocating punch and bed
  • B26F1/04—Perforating by punching, e.g. with relatively-reciprocating punch and bed with selectively-operable punches
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
  • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
  • B26D7/18—Means for removing cut-out material or waste
  • B26D7/1818—Means for removing cut-out material or waste by pushing out
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/02—Perforating by punching, e.g. with relatively-reciprocating punch and bed

Definitions

• This invention relates to punches and to a punch assembly.
• Flexible photopolymer sheeting as is used extensively in the printing industry, is known to comprise a hard plastics cover sheet, an acetate backing sheet with a soft photopolymer filler between the sheets.
• a registration bar in association with the print roll, and which bears registration pins adjustable as to their position on the bar, and to provide corresponding holes in the photopolymer sheeting.
• the photopolymer sheeting is first located by its holes on the appropriate registration pins and the free end of the sheeting wrapped onto the roll, following which the sheeting is released from the registration bar and wrapping of the sheeting on to the roll completed.
• a punch assembly for flexible photopolymer material comprises a hollow tubular punch member which, at its operative end is correspondingly inwardly contoured at diametrically opposite sides, and a support plate or die, the punch being mounted above the support plate for axial reciprocal movement towards and away from the support plate and there being a corresponding hole in the support plate for the passage of the punch.
• a hollow tubular punch member which, at its operative end is correspondingly inwardly contoured at diametrically opposite sides
• a support plate or die the punch being mounted above the support plate for axial reciprocal movement towards and away from the support plate and there being a corresponding hole in the support plate for the passage of the punch.
• an ejector pin is provided within and mounted for reciprocal movement with respect to the punch.
• the punch is provided with two diametrically opposite protruding cutting edges and which facilitate to a considerable degree the passage of the punch through materials such as flexible photopolymer sheeting and with flexible photopolymer sheeting located on the support plate below the punch, a rapid movement of the punch towards the "sheeting allows the punch to pass cleanly through the sheeting to punch a hole therein, and with the punch extending through the hole in the support plate, the ejector pin is " activated to remove the plug of the photopolymer sheeting from within the punch and deposit into a suitable receptacle below the support plate. Further preferably, a clamping means is provided to hold the flexible photopolymer material during movement of the punch.
• the punch can be secured to a pi ston w ithin a cylinder, and emerge from the cylinder, and the selective application of compressed air to one side or the other of the piston causes a rapid forward and return stroke of the punch.
• the piston for the punch can itself be cylindrical, and within which can be located a second piston attached to which is the ejector pin that extends through the end walls of the piston and down through the punch, selective application of compressed air to one side or the other of the second piston causing a rapid forward and return stroke of the ejector pin.
• the clamping means can be pneumatically operated.
• Figure 1 is a perspective view of a machine embodying the invention
• Figure 2 is a schematic front elevation of a part of Figure 1 and to a larger scale showing the punch assemblies of Figure 1;
• Figure 3 is a sectional side elevation of a punch assembly according to the invention.
• equipment including punch assemblies of the invention comprises a cabinet 1 supporting a flat bed 2 and having two upright support pillars 3, one to- either side of the cabinet. Between the support pillars 3, a housing 4 is provided containing the punch assemblies and which are described in greater below.
• a compressor and required electrical control equipment (not shown), and to the front of the cabinet two switches 5 and 6 are provided to be activated by the foot of the operative.
• a first transverse support member 7 extending between the pillars 3 on which are located a number of punch assemblies 8.
• a guide bar 9 having guide holes for the punches 10 of the punch assemblies, and also extending between the pillars 3 is a die bar 11 having holes in register with the punches of the punch assemblies, and in which the punches are a close sliding fit.
• a movable clamping bar 12 activated by a pneumatic cylinder 13 to each end of the bar.
• the punch assemblies 8 are each connected to a common source of compressed air by pneumatic air lines 14 and 15 for effecting the drive and return strokes of the punch assembly as will be described in greater detail below, and there being a shut-off valve 16 in the ai line for the drive stroke of each punch assembly to allow for the selective activation of the punch assemblies.
• each punch assembly has a support member 17 to enable the punch assembly to be secured to the support bar 7 and which supports a cylinder 18 within which is a piston 19 to which the punch 10 is attached, there being air passageways 21, 22 through the cylinder to enable compressed air to be provided selectively above and below the piston and to effect the drive and return stroke of the punch 10.
• the piston 19 serves additionally as a cylinder for a piston 23 of an ejector pin 24 extending through the punch 19.
• the upper end of the piston 19 has a cylindrical extension 25 with an outer end 26 of reduced diameter, extending into a counterbore 27 in a top end cap 28 to the cylinder 18.
• the cutting end of the punch is provided with a contoured profile 25 and to be correspondingly inwardly contoured at diametrically opposite sides.
• a flexible photopolymer sheeting is placed on the bed 2 and positioned on the bed 2 such that one edge extends to an appropriate degree beyond the line of the punch assemblies 8 and is so oriented that the sheeting is correctly located in relation to the plane of the punch assmblie ⁇ .
• the switch 5 is activated to admit pressure air to the cylinder 13 and to cause the clamp plate to clamp the polymer sheeting to the die bar 11.
• the switch 6 is activated to admit pressure air to the cylinders 18 to effect a drive stroke of the punches 10, with either all of the punches 10 simultaneously activated, or dependent upon the pattern of holes to be punched in the photopolymer sheeting, a number of the isolating switches 16 activated to hold required punch assemblies 8 inactive and whereby to punch a required pattern of holes in the photopolymer sheeting, followed immediately by the drive strokes to the ejector pins, to deposit the slug of photopolymer sheeting from within the punch into a suitable receptacle located within the cabinet 1.
• the switches 5 and 6 are de-activated to cause the return of the punches and the return of the clamping bar.
• the co-operation between the die bar and the contoured cutting edge of the punch and the rapidity of movement of the punch is such that holes are punched in the photopolymer sheeting of the accuracy that is demanded by the subsequent use of the photopolymer sheeting and their location on registration pins in printing equipment.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10654578

Family Applications (1)

Country Status (4)

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Family Cites Families (11)

• 1989
  • 1989-04-06 GB GB898907795A patent/GB8907795D0/en active Pending
• 1990
  • 1990-04-05 WO PCT/GB1990/000515 patent/WO1990011876A1/en not_active Ceased
  • 1990-04-05 EP EP19900905584 patent/EP0466761A1/de not_active Withdrawn
  • 1990-04-05 AU AU54184/90A patent/AU5418490A/en not_active Abandoned

Non-Patent Citations (1)

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