Apparatus for perforating a web of flexible film

Claim 2

Apparatus for perforating a web on transverse lines spaced longitudinally of the web comprising: means for feeding the web through the apparatus at a substantially constant speed comprising a rotary back-up roll and means for driving the back-up roll at a substantially constant speed; a perforator having at least one perforating blade for forming transverse lines of perforations in the web as it travels over the back-up roll, said perforator comprising a plurality of perforating blades spaced at equal angular intervals therearound, a shaft of square cross section thereby having four faces, and means on each of said faces for removably mounting a perforating blade with the blade extending radially outwardly from the shaft; means mounting said perforator for rotation on an axis parallel to the axis of the back-up roll for movement toward and away from the back-up roll thereby to position the perforating blade to perforate through the web on the back-up roll; and means for driving the perforator.

Claim 3

Apparatus for perforating a web on transverse lines spaced longitudinally of the web comprising: means for feeding the web through the apparatus at a substantially constant speed comprising a rotary back-up roll and means for driving the back-up roll at a substantially constant speed; a perforator having at least one perforating blade for forming transverse lines of perforations in the web as it travels over the back-up roll; means mounting said perforator for rotation on an axis parallel to the axis of the back-up roll and for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll; means for driving the perforator; and a frame in which the back-up roll is journalled for rotation on a horizontal axis, said perforator comprising a shaft and a blade holder removably mounted on the shaft carrying the perforating blade, and the means mounting the perforator for rotation and for movement toward and away from the back-up roll comprising a pair of arms pivoted on the frame for swinging movement on an axis parallel to the axis of the back-up roll, the shaft extending between and being journalled in the arms for rotation about its said axis parallel to the axis of the back-up roll, said arms being swingable to adjust the shaft to different fixed positions relative to the back-up roll for use of blade holders of different size, and said shaft being of square cross section thereby having four faces, with means on each of said four faces for removably mounting a blade holder.

Claim 4

Apparatus for perforating a web on transverse lines spaced longitudinally of the web comprising: means for feeding the web through the apparatus at a substantially constant speed comprising a rotary back-up roll and means for driving the back-up roll at a substantially constant speed; a perforator having at least one perforating blade for forming transverse lines of perforations in the web as it travels over the back-up roll; means mounting said perforator for rotation on an axis parallel to the axis of the back-up roll and for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll; means for driving the perforator; and a frame in which the back-up roll is journalled for rotation on a horizontal axis, said perforator comprising a shaft and a blade holder removably mounted on the shaft carrying the perforating blade, and the means mounting the perforator for rotation and for movement toward and away from the back-up roll comprising a pair of arms pivoted on the frame for swinging movement on an axis parallel to the axis of the back-up roll, the shaft extending between and being journalled in the arms for rotation about its said axis parallel to the axis of the back-up roll, said arms being swingable to adjust the shaft to different fixed positions relative to the back-up roll for use of blade holders of different size, and said shaft being of square cross section thereby having four faces, with means on each of said four faces for removably mounting a blade holder.

Claim 5

Apparatus as set forth in claim 2 wherein the mounting means on each of said four faces and the respective blade holder are formed for endwise sliding engagement of the holder with said mounting means.

Claim 6

Apparatus as set forth in claim 3 further having means for releasably fastening each blade holder in place after it has been slidably engaged with the respective mounting means.

Claim 7

Apparatus for perforating a web on transverse lines spaced longitudinally of the web comprising: means for feeding the web through the apparatus at a substantially constant speed comprising a frame, a rotary back-up roll journalled in said frame for rotation on a horizontal axis, and means for driving the back-up roll at a substantially constant speed; a perforator having at least one perforating blade for forming transverse lines of perforations in the web as it travels over the back-up roll, said perforator comprising a shaft and a blade holder removably mounted on the shaft carrying the perforator blade; means mounting said perforator for rotation on an axis parallel to the axis of the back-up roll and for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll, said perforator mounting means comprising a pair of arms pivoted on the frame for swinging movement on an axis parallel to the axis of the back-up roll, the shaft extending between and being journalled in the arms for rotation about its axis parallel to the axis of the back-up roll, said arms being swingable to adjust the different fixed positions relative to the back-up roll for use of blade holders of different size; and means for determining the adjusted positions of the shaft and retaining the shaft therein comprising at least one series of locating holes in the arms and locating pins carried by the frame receivable in the holes.

Claim 8

Apparatus for perforating a web on transverse lines spaced longitudinally of the web comprising: means for feeding the web through the apparatus at a substantially constant speed comprising a frame, a rotary back-up roll journalled in said frame for rotation on a horizontal axis, and means for driving the back-up roll at a substantially constant speed; a perforator having at least one perforating blade for forming transverse lines of perforations in the web as it travels over the back-up roll, said perforator comprising a shaft and a blade holder removably mounted on the shaft carrying the perforator blade; means mounting said perforator for rotation on an axis parallel to the axis of the back-up roll and for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll, said perforator mounting means comprising a pair of arms pivoted on the frame for swinging movement on an axis parallel to the axis of the back-up roll, the shaft extending between and being journalled in the arms for rotation about its axis parallel to the axis of the back-up roll, said arms being swingable to adjust the different fixed positions relative to the back-up roll for use of blade holders of different size; and means for determining the adjusted positions of the shaft and retaining the shaft therein comprising at least one series of locating holes in the arms and locating pins carried by the frame receivable in the holes.

Claim 9

Apparatus for perforating a web on transverse lines spaced longitudinally on the web comprising means for feeding the web through the apparatus at substantially constant speed including a rotary back-up roll and means for driving the back-up roll at a substantially constant speed, a perforator for forming transverse lines of perforations in the web as it travels over the back-up roll comprising a shaft having an equal number of faces thereon, means on each of the faces for removably mounting a perforating blade with the blade extending radially outwardly from the shaft, the perforating blades defining a pitch circle having a pitch diameter, said mounting means further comprising a pair of mounting blocks on each face of the shaft, each pair of said mounting blocks having a dovetail groove therein for reception of a perforating blade, each of said perforating blades being slidable endwise parallel to said shaft into said dovetail groove in said mounting block, each said mounting block having means for locking a respective said perforating blade relative thereto, means mounting the perforator for rotation on an axis parallel to the axis of the back-up roll for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll, and means for driving the perforator, whereby the spacing of the lines of perforations formed in the web may be varied by installing one or an even number of perforating blades on opposite faces of said shaft thereby to vary the number of times a perforating blade contacts the back-up roll on each revolution of the perforator and/or by installing sets of perforating blades on said shaft having different heights, each blade in each set being of the same height, thereby to vary the pitch diameter of said perforating blades and to vary the spacing between the lines of perforations formed each time a perforating blade contacts the back-up roll.

Claim 10

Apparatus for perforating a web on transverse lines spaced longitudinally on the web comprising means for feeding the web through the apparatus at substantially constant speed including a rotary back-up roll and means for driving the back-up roll at a substantially constant speed, a perforator for forming transverse lines of perforations in the web as it travels over the back-up roll comprising a shaft having an equal number of faces thereon, means on each of the faces for removably mounting a perforating blade with the blade extending radially outwardly from the shaft, the perforating blades defining a pitch circle having a pitch diameter, said mounting means further comprising a pair of mounting blocks on each face of the shaft, each pair of said mounting blocks having a dovetail groove therein for reception of a perforating blade, each of said perforating blades being slidable endwise parallel to said shaft into said dovetail groove in said mounting block, each said mounting block having means for locking a respective said perforating blade relative thereto, means mounting the perforator for rotation on an axis parallel to the axis of the back-up roll for movement toward and away from the back-up roll for positioning the perforating blade to perforate through the web on the back-up roll, and means for driving the perforator, whereby the spacing of the lines of perforations formed in the web may be varied by installing one or an even number of perforating blades on opposite faces of said shaft thereby to vary the number of times a perforating blade contacts the back-up roll on each revolution of the perforator and/or by installing sets of perforating blades on said shaft having different heights, each blade in each set being of the same height, thereby to vary the pitch diameter of said perforating blades and to vary the spacing between the lines of perforations formed each time a perforating blade contacts the back-up roll.

Claim 11

Apparatus as set forth in claim 6 wherein the shaft is of square cross section thereby havinG four faces.