EP1260326A2

EP1260326A2 - Method and apparatus for partially cutting a sheet, and sheet or strip obtained thereby

Info

Publication number: EP1260326A2
Application number: EP02253639A
Authority: EP
Inventors: Adrian Llewellyn Merritt
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-05-23
Filing date: 2002-05-23
Publication date: 2002-11-27
Also published as: GB2375729A; GB2375729B; EP1260326A3; GB0112532D0

Abstract

A cutting apparatus (1) is provided for cutting at least one sheet, for example in the form of a strip (8) into two or more partially joined pieces for example in the form of pads, which apparatus comprises support means (2) and cutting means (7). The support means or the cutting means or the support means and the cutting means are provided with at least one recess (4). In use, the strip (8) is positioned between the support means (2) and the cutting means (7) such that a force is applied to the strip (8) causing a portion thereof to be placed in the or each recess (4) and the strip (8) to be partially cut at the portion contained in the or each recess and to be wholly cut at a portion not contained in the or each recess.

The depth of the or each recess preferably lies in the range 50 to 100 µm, and the width of the or each recess preferably lies in the range 0.5 to 1 mm. The or each recess preferably has a substantially rectangular cross section. The or each recess may be formed by a groove. The cutting means preferably cuts the strip in a direction substantially 90° to the length of the strip.

Description

This invention relates to improvements in and relating to cutting materials, and particularly, but not exclusively, to cutting sheets of material into strips and/or cutting strips of material into pads.

Numerous applications exist where it is necessary to cut materials into pieces. For example, in the glass industry pads are used to space apart sheets of glass. These pads may be formed from materials such as cork or foam or a cork/foam laminate. Conveniently, a strip of material is cut into pads which are partially joined to each other. For application to a sheet of glass, the strip may be passed into an applicator machine, such as a Lenhardt applicator machine. In these, a strip of spacer pads is pushed into a position such that one pad protrudes from a part of the machine. The protruding pad is contacted to the surface of a sheet of glass as it moves through the machine. This causes the pad to be pulled away and separate from the strip of pads. A method of contacting and separating a pad is to use a roller (or rollers) to help maintain the position of the pad and/or glass and join them together. The roller (or rollers) traps the pad between itself and the sheet of glass, and the movement of the glass causes the pad to be pulled away and to separate from the strip of pads. Other methods may be used. Eventually the pads space the sheets of glass to prevent damage when stacked. Conventionally, such machines have operated with strips of cork/foam laminate pads. Each pad comprises a cork portion to which a layer of foam is laminated. A strip of pads is formed by laminating a strip of cork with a corresponding strip of foam, and cutting the composite strip through the cork and partially through the foam at a number of locations to form a number of pads partially joined to one another. When such a strip of pads is passed through a Lenhardt applicator machine, the endmost pad to be applied to a sheet of glass is caused to protrude from the end of the strip of pads but is held to the strip by the uncut portion of the foam layer. As the sheet of glass sweeps past the pad and the roller engages with it, the pad is pulled away from the remainder of the strip of pads and the uncut portion of the foam breaks, releasing the pad from the strip. The foam is conventionally of low performance, such that partial cutting thereof is sufficient to allow the uncut portion to break without undue force being necessary. Separation of a pad from a strip of such pads can also be effected by hand.

A problem arises when it is desired to replace the strip of cork/foam laminate pads with a strip of foam only pads. Such foam pads may be of a singular foam construction or a laminate of different foam structures and may be non-adhesive or may have adhesive on one or more faces thereof. The pads may be provided with a backing paper. Such pads are often formed of high performance foam material such that, even with partial cutting, the uncut portion is prone to stretching and is difficult to break away from the remainder of a strip of such pads. This makes such strips of pads difficult to use in the above described applicator machines or manually. To reliably break the uncut portion of such pads it is necessary to make the thickness of this portion very small, which can be difficult to reproduce. Even providing perforations between the pads can lead to stretching rather than breaking.

It is known from US 3 255 948 and EP 0 841 649 to use blades of varying profile to produce perforations in a sheet product. More specifically US 3 255 948 uses two different blades to perforate a card product, a first blade being configured as a series of blade sections separated by recesses and a second blade being continuous, in use the second blade is positioned lower than the first. EP 0 841 649 discloses use of blades of varying heights to produce perforations, preferably in a paper product such as a self-adhesive stamp.

According to a first aspect of the present invention there is provided a cutting apparatus for cutting at least one sheet into two or more partially joined pieces comprising support means and cutting means, the support means or the cutting means or the support means and the cutting means being provided with at least one recess, wherein, in use, the sheet is positioned between the support means and the cutting means such that a force is applied to the sheet causing a portion thereof to be placed in the or each recess and the sheet to be partially cut at the portion contained in the or each recess and to be wholly cut at a portion not contained in the or each recess.

The portion of the sheet placed in the or each recess may be pushed or pulled into the recess. The portion of the sheet contained in the or each recess will be partially cut along its thickness, depending on the depth of the recess. The remaining portion or portions of the sheet will be cut throughout the thickness thereof. Two or more partially joined pieces are therefore obtained, the pieces being joined by one or more bridges whose height is less than the thickness of the sheet. It is possible to accurately control the depth of the or each recess, and therefore achieve accurate and reproducible height of the bridges.

The sheet may comprise a relatively soft yet resilient material, which may be rushed into the recesses without causing damage to the material, but resilient enough to receive its shape when removed from the recess.

The sheet may be cut into two or more partially joined strips. Each strip may be cut into two or more partially joined strips. Each strip may be cut into two or more partially joined pads. This may occur simultaneously with, or prior to, or subsequently to, cutting of the sheet or strip into two or more partially joined strips.

The strips may be wound onto a roll so that they lie substantially in line with themselves and/or adjoining strips. Guiding means may be used to wind the strips onto the roll so that they lie substantially in line. Each strip or some of the strips on the roll may be separately unwound from the roll, breaking away from its or their neighbouring strip or strips during unwinding. The remaining strips preferably remain intact and in place on the roll during this unwinding. This may have significant benefits by negating the need to rewind material(s) into individual strips or rolls prior to further processing and/or use.

The sheet may comprise a strip, which may be cut into two or more partially joined pads.

The sheet may be elongate, e.g. have a length of 50 or 100m or longer. The sheet may have a substantial width, e.g. around 1m. Such a sheet may be cut into pieces having a width of, for example, 18 or 250mm, i.e. may be cut into strips. The sheet may have a much smaller width, e.g. around 18 or 250mm. Such a sheet, or strip, may be cut in a direction substantially transverse to the length thereof to form pads. Such a strip may be cut in a direction substantially along the length thereof to form strips, including strips of pads. The term pad is herein intended to include structures which are substantially square in shape, and structures which are substantially rectangular in shape. The latter may have a considerable length in one direction in comparison to the transverse direction. Other shapes may be cut.

The support means or the cutting means is preferably provided with at least three recesses, but could have one or two or four or five or more recesses. Such an apparatus will produce a sheet of partially joined pieces wherein the pieces are joined by three or one or two or four or five or more bridges. Providing two bridges will help to prevent the pieces from twisting as, for example, they protrude from an applicator machine for application to a sheet of glass. Providing three or more bridges will help to prevent such twisting even if one or more of the bridges should break. The depth of the or each recess preferably lies in the range 50 to 100 µm, but could be more or less than this depth. When more than one recess is provided, these may have substantially the same depth or may have different depths. The width of the or each recess preferably lies in the range 0.5 to 1 mm, but could be more or less than this width. Different materials and/or different thicknesses of material may require a different recess depth and/or recess width. When more than one recess is provided, these may have substantially the same width or may have different widths. The or each recess may have a substantially rectangular cross section, or may have a substantially U-shaped cross section or may have a substantially V-shaped cross section, or a differently-shaped cross section. The support means or the cutting means may be provided with one or more grooves or one or more cut-outs which form one or more recesses.

The cutting means may cut the sheet in a direction substantially transverse to the length of the sheet, or in a direction substantially parallel to the length of the sheet, or in both the substantially transverse and parallel directions. The support means and the cutting means may act to feed the sheet through the apparatus. The apparatus may be provided with pulling means, or pushing means, or pulling means and pushing means by which the sheet is fed through the apparatus. Alternatively, pulling means, or pushing means, or pulling means and pushing means, external to the apparatus may be provided to feed the sheet through the apparatus. The pulling means/pushing means may pull/push the strip through the apparatus in a direction substantially parallel to the length of the sheet. The sheet may be cut in a substantially transverse direction to the direction of feed of the sheet through the apparatus, or in a substantially parallel direction to the direction of feed of the sheet through the apparatus, or in both such directions.

The support means may remain stationary whilst the cutting means is moved. Alternatively, the cutting means may remain stationary whilst the support means is moved. Alternatively, the cutting means and the support means may be moved. Such movement(s) may result in movement of the sheet through the apparatus, without the need for additional pulling or pushing means.

The cutting means may comprise one or more blades. The cutting means may comprise one or more blades provided on one or more plate-like elements. The plate-like elements may be attached together or may be separate from each other. The cutting means may comprise one or more circular blades. The circular blades may be attached together or may be separate from each other. The cutting means may comprise a single continuous cutting edge in a single plane. Such a blade can be easily sharpened and maintained. The cutting means may comprise a cutting mandrel with one or more blades incorporated therein or fixed thereto. The blades may be provided with one or more recesses.

The support means may comprise a support mandrel. The cutting means may be provided on a cutting mandrel. The support mandrel may be provided with one or more recesses which extend around a part of, or the whole of, or substantially the whole of the circumference of the support mandrel. The support mandrel may be provided with one or more recesses which extend axially along a part of, or the whole of, or substantially the whole of the support mandrel. The support mandrel may be provided with one or more recesses which extend spherically around a part of, or the whole of, or substantially the whole of the support mandrel. The cutting mandrel may be provided with one or more recesses which extend around a part of, or the whole of, or substantially the whole of the circumference of the cutting mandrel. The cutting mandrel may be provided with one or more recesses which extend axially along a part of, or the whole of, or substantially the whole of the cutting mandrel. The cutting mandrel may be provided with one or more recesses which extend spherically around a part of, or the whole of, or substantially the whole of the cutting mandrel. The cutting mandrel may be provided with cutting means which extend circumferentially or axially along or spherically around a part of, or the whole of, or substantially the whole of the cutting mandrel. The cutting means may be provided with one or more recesses.

In one embodiment of the apparatus, the support means may comprise a support mandrel provided with one or more circumferential recesses and axial cutting means may be provided on a cutting mandrel. The axial cutting means may comprise one or more axial blades. In this case, the sheet may be fed through the apparatus in a direction substantially perpendicular to the axes of the mandrels, to cut the sheet in a direction substantially transverse to the length thereof. The sheet may comprise a strip, which may be cut into two or more partially joined pads.

In another embodiment of the apparatus, the support means may comprise a support mandrel provided with one or more axial recesses, or one or more groups of one or more axial recesses, and circumferential cutting means may be provided on a cutting mandrel. The circumferential cutting means may comprise one or more circumferential blades. In this case, the sheet may be fed through the apparatus in a direction substantially parallel to the axes of the mandrels, to cut the sheet in a direction substantially transverse to the length thereof. The sheet may comprise a strip which may be cut into two or more partially joined pads.

Alternatively, the sheet may be fed through the apparatus in a direction substantially perpendicular to the axes of the mandrels, to cut the sheet in a direction substantially parallel to the length thereof. The sheet may thereby be cut into partially joined strips. Each strip, or some or all of the strips together, may then be fed through the apparatus in a direction substantially parallel to the axes of the mandrels, to cut the strip in a direction substantially transverse to the length thereof to form pads.

In another embodiment, the sheet may be simultaneously cut in a direction parallel to the axes of the mandrels and perpendicular to the axes of the mandrels.

The support mandrel and the cutting mandrel may co-operate, in use, to provide a distance between the support mandrel and the cutting means of the cutting mandrel which is less than the thickness of a sheet to be cut. When the sheet is placed between the mandrels it will be compressed by the cutting means, to force a portion of the sheet into the or each recess in the support mandrel or the cutting mandrel or both, thus allowing partially joined pieces to be formed from the sheet.

The sheet may be provided with a backing sheet.

The support mandrel and the cutting mandrel may co-operate, in use, to provide a distance between the support mandrel and the cutting means of the cutting mandrel which is equal to the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the mandrels it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support mandrel or the cutting mandrel or both, and the cutting means will partially cut the sheet but will not cut the backing sheet. The thickness of the sheet which is left uncut will be affected by the depth of the or each recess. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. The thickness of the sheet which is left uncut will still be affected by the depth of the or each recess. Compression of the sheet and/or backing sheet may also affect the thickness of the sheet which is left uncut.

Alternatively, or additionally the support mandrel and the cutting mandrel may co-operate, in use, to provide a distance between the support mandrel and the cutting means of the cutting mandrel which is less than the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the mandrels it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support mandrel or the cutting mandrel or both. The cutting means may partially cut the backing sheet and/or may partially or wholly cut the sheet, depending on the distance provided between the support mandrel and the cutting means of the cutting mandrel, the depth of the or each recess and the thickness of the backing sheet. For example, the apparatus may operate such that the cutting means may meet the support mandrel, i.e. the distance between the support mandrel and the cutting means of the cutting mandrel is approximately zero. The or each recess may contain a part of the thickness of the portion of the backing sheet, and the cutting means will partially cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet, and the cutting means will not cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet and a portion of the sheet, and the cutting means will not cut the backing sheet and will partially cut the sheet. Which of the above that occurs, will depend on the depth of the or each recess and the thickness of the backing sheet. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. This will affect the thickness of the backing sheet and/or sheet which is left uncut. Compression of the sheet and/or backing sheet may also affect the thickness of the backing sheet and/or sheet which is left uncut.

The support mandrel may be a rotary mandrel. The cutting mandrel may be a rotary mandrel. The support mandrel and the cutting mandrel may rotate at a similar speed or at different speeds, in the same direction or in opposite directions. Alternatively, the support mandrel may remain stationary whilst the cutting mandrel rotates, or the cutting mandrel may remain stationary whilst the support mandrel rotates. The support mandrel or the cutting mandrel or the support mandrel and the cutting mandrel may be provided with one or more shoulder portions. The or each shoulder portion may enable the mandrels to co-operate in use. The support mandrel and the cutting mandrel may be connected together. A gear system may be provided at one or both ends of the support mandrel or the cutting mandrel or the support mandrel and the cutting mandrel.

The apparatus may comprise more than one support mandrel. The apparatus may comprise more than one cutting mandrel. The apparatus may comprise more than one set of co-operating support and cutting mandrels.

The support means may comprise a support mandrel. The cutting means may then comprise one or more circular blades. When more than one blade is provided, these may be attached together or may be separate from each other. The blade or blades may be rotary. The support mandrel or the cutting means or the support mandrel and the cutting means may be provided with one or more recesses. The support mandrel and the cutting means may co-operate, in use, to provide a distance between them which is less than the thickness of a sheet to be cut. The support mandrel and the cutting means may co-operate to leave little or no distance between them. When the sheet is placed between the support mandrel and the cutting means it will be compressed by the cutting means, to force a portion of the sheet into the or each recess in the support mandrel or the cutting means or both. The cutting means cuts all but the material in the recess or recesses, thus allowing partially joined pieces to be formed from the sheet.

The sheet may be provided with a backing sheet. The support mandrel and the cutting means may co-operate, in use, to provide a distance between them which is equal to the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the support mandrel and the cutting means it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support mandrel or the cutting means or both, and the cutting means will partially cut the sheet but will not cut the backing sheet. The thickness of the sheet which is left uncut will be affected by the depth of the or each recess. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. The thickness of the sheet which is left uncut will still be affected by the depth of the or each recess. Compression of the sheet and/or backing sheet may also affect the thickness of the sheet which is left uncut.

The sheet may be provided with a backing sheet. The support mandrel and the cutting means may co-operate, in use, to provide a distance between them which is less than the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the support mandrel and the cutting means it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support mandrel or the cutting means or both. The cutting means may partially cut the backing sheet and/or may partially or wholly cut the sheet, depending on the distance provided between the support mandrel and the cutting means, the depth of the or each recess and the thickness of the backing sheet. For example, the apparatus may operate such that the cutting means may meet the support mandrel, i.e. the distance between the support mandrel and the cutting means is approximately zero. The or each recess may contain a part of the thickness of the portion of the backing sheet, and the cutting means will partially cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet, and the cutting means will not cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet and a portion of the sheet, and the cutting means will not cut the backing sheet and will partially cut the sheet. Which of the above that occurs, will depend on the depth of the or each recess and the thickness of the backing sheet. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. This will affect the thickness of the backing sheet and/or sheet which is left uncut. Compression of the sheet and/or backing sheet may also affect the thickness of the backing sheet and/or sheet which is left uncut.

The support mandrel and the blades of the cutting means may co-operate in use by movement of the blades whilst the support mandrel is held stationary or movement of the support mandrel whilst the blades are held stationary, or movement of both the support mandrel and the blades.

The support means may comprise a flat bed. The cutting means may then be provided on a flat bed, or on one or more plate-like elements or on a cutting mandrel. The support flat bed or the cutting means or the support flat bed and the cutting means may be provided with one or more recesses. The support flat bed and the cutting means may co-operate, in use, to provide a distance between them which is less than the thickness of a sheet to be cut. The support flat bed and/or the cutting means may move up and/or down to co-operate, in use, to provide a distance between them which is less than the thickness of a sheet to be cut. When the sheet is placed between the support flat bed and the cutting means it will be compressed by the cutting means, to force a portion of the sheet into the or each recess in the support flat bed or the cutting means or both, thus allowing partially joined pieces to be formed from the sheet.

The sheet may be provided with a backing sheet. The support flat bed and the cutting means may co-operate, in use, to provide a distance between them which is equal to the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the support flat bed and the cutting means it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support flat bed or the cutting means or both, and the cutting means will partially cut the sheet but will not cut the backing sheet. The thickness of the sheet which is left uncut will be affected by the depth of the or each recess. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. The thickness of the sheet which is left uncut will still be affected by the depth of the or each recess. Compression of the sheet and/or backing sheet may also affect the thickness of the sheet which is left uncut.

The sheet may be provided with a backing sheet. The support flat bed and the cutting means may co-operate, in use, to provide a distance between them which is less than the thickness of the backing sheet. When the combined sheet and backing sheet is placed between the support flat bed and the cutting means it will be compressed by the cutting means, to force a portion of the backing sheet, or a portion of the sheet and the backing sheet, into the or each recess in the support flat bed or the cutting means or both. The cutting means may partially cut the backing sheet and/or may partially or wholly cut the sheet, depending on the distance provided between the support flat bed and the cutting means, the depth of the or each recess and the thickness of the backing sheet. For example, the apparatus may operate such that the cutting means may meet the support flat bed, i.e. the distance between the support flat bed and the cutting means is approximately zero. The or each recess may contain a part of the thickness of the portion of the backing sheet, and the cutting means will partially cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet, and the cutting means will not cut the backing sheet and will wholly cut the sheet. The or each recess may contain the whole of the thickness of the portion of the backing sheet and a portion of the sheet, and the cutting means will not cut the backing sheet and will partially cut the sheet. Which of the above that occurs, will depend on the depth of the or each recess and the thickness of the backing sheet. The backing sheet may be coated with, for example, adhesive or silicon or adhesive and silicon. This will affect the thickness of the backing sheet and/or sheet which is left uncut. Compression of the sheet and/or backing sheet may also affect the thickness of the backing sheet and/or sheet which is left uncut.

The support flat bed and the cutting means may co-operate in use by movement of the cutting means whilst the support flat bed is held stationary or movement of the support flat bed whilst the cutting means is held stationary, or movement of both the support flat bed and the cutting means. For example, the cutting means may comprise a blade which may be moved in a substantially vertical direction into and out of co-operation with the support flat bed.

The sheet may comprise a foam material, for example a PVC foam material. The foam material is preferably such that the force required to be applied to a piece to break it from the sheet is substantially or less than 10N, when the force is applied to the piece at a rate of approximately 500mm/min. The force required to break a piece from the sheet may be more than this figure. The sheet may comprise a paper material. The sheet may comprise a coated paper, for example a paper coated with pressure sensitive adhesive or a paper coated with silicon. The sheet may comprise a filmic material, for example a polyester material or a polypropylene material or a polyethylene material which may be a high density polyethylene material and which may be coated with silicon. The sheet may comprise a board material. The sheet may comprise a fabric material. The sheet may comprise two or more materials laminated together. For example, the sheet may comprise a foam material combined with or laminated to a paper material. The sheet may comprise a unitary piece formed from two or more materials.

The sheet may be provided with a backing sheet. The sheet may be provided with adhesive on one or both longitudinal faces thereof. The sheet may be provided with adhesive on one or both longitudinal faces thereof, and a backing sheet may be provided to cover the or each adhesive carrying face. The backing sheet may comprise release paper.

According to a second aspect of the present invention there is provided a sheet which comprises two or more partially joined pieces formed by the apparatus of the first aspect of the invention.

The sheet may comprise a foam material, for example a PVC foam material. The foam material is preferably such that the force required to be applied to a piece to break it from the sheet is substantially or less than 10N, when the force is applied to the piece at a rate of approximately 500mm/min. The force required to break a piece from the sheet may be more than this figure. The sheet may comprise a paper material. The sheet may comprise a coated paper, for example a paper coated with pressure sensitive adhesive or a paper coated with silicon. The sheet may comprise a filmic material, for example a polyester material or a polypropylene material or a polyethylene material which may be a high density polyethylene material and which may be coated with silicon. The sheet may comprise two or more materials laminated together. For example, the sheet may comprise a foam material combined with or laminated to a paper material. The sheet may comprise two or more layers of the same, or substantially the same, material with each layer having different material properties.

The sheet may be provided with a backing sheet. The sheet may be provided with adhesive on one or both longitudinal faces thereof. The sheet may be provided with adhesive on one or both longitudinal faces thereof, and a backing sheet may be provided to cover the or each adhesive carrying face. The sheet may be provided with adhesive on one or both edge faces thereof. The sheet may be provided with adhesive on one or both edge faces thereof, and a backing sheet may be provided to cover the or each adhesive carrying face. The backing sheet may comprise release paper.

According to a third aspect of the present invention there is provided a method for cutting a sheet into two or more partially joined pieces comprising applying the sheet to an apparatus according to the first aspect of the invention and operating the apparatus to bring the cutting means into contact with the sheet to cut the sheet into two or more partially joined pieces.

The method may comprise cutting a sheet of foam material of, for example, 1m width and 50m length, in a direction substantially parallel to the length thereof to form partially joined strips of, for example, 250mm width and 50m length. The method may further comprise cutting a sheet of paper material of, for example, 1m width and 50m length, in a direction substantially parallel to the length thereof to form partially joined strips of, for example, 250mm width and 50m length. The foam strips and the paper strips may be wound onto separate rolls so that the strips on each roll lie substantially in line with themselves and/or adjoining strips. A foam strip may be unwound from its roll, breaking away from its neighbouring strip or strips during unwinding, and a paper strip may be unwound from its roll, breaking away from its neighbouring strip or strips during unwinding. The remaining strips preferably remain intact and in place on their roll during this unwinding. The foam strip and the paper strip may be joined, for example by adhesive which may be present on the foam or the paper or on both the foam and the paper. The joined strip may be cut in a direction substantially parallel to the length thereof to form partially joined strips of, for example, 18mm width and 50m length. These strips may be cut in a direction substantially perpendicular to the length thereof to form partially joined pads, for example, substantially 18mm square pads. This may occur simultaneously with, or prior to, or subsequently to, cutting of the strip into two or more partially joined strips. Alternatively, the joined strip may be cut in a direction substantially perpendicular to the length thereof to form partially joined pads.

According to a fourth aspect of the present invention there is provided a strip which comprises two or more partially joined pads formed by the apparatus of the first aspect of the invention.

According to fifth, sixth, seventh and eighth aspects of the present invention there is provided a roll or rolls and/or a spool or spools of the strip according to the fourth aspect of the invention.

According to a ninth aspect of the present invention there is provided a pad which has been separated from a strip according to the fourth aspect of the invention.

The pad may be used as a glass spacer pad to separate two sheets of glass from one another. The pad may be used as a marker, for example for sheets of glass to mark parts of the sheet which may be a hazard in the workplace. A rectangularly shaped pad is particularly useful in such applications, but other shapes may be used. The pads may be used as packing elements.

According to another aspect of the present invention there is provided a glass spacer pad applicator machine comprising a cutting apparatus according to the first aspect of the invention.

According to another aspect of the present invention there is provided a glass spacer pad applicator machine which applies precut pads according to the ninth aspect of the invention, where a backing sheet or release paper has been removed from one, two or more pads prior to the application of the pad to the glass.

According to another aspect of the invention a method of cutting a sheet into two or more partially joined pieces comprises feeding or positioning the sheet between a support means and a cutting means, applying force to the sheet to push a portion of the sheet into one or more recesses in the support means, operating the cutting means to bring the cutting means into contact with the sheet, cutting the sheet partially at a sheet portion or portions contained in the or each recess.

The method may comprise cutting the sheet into two or more partially joined strips, which may be then cut into a further two or more partially joined strips. The strips may be cut into two or more partially joined parts.

The method may comprise providing a support means with three recesses. The depth of the or each recess may lie in the range 50 to 100mm, and may have a width in the range 0.5 to 1mm.

The method may comprise providing a support means with one or more recesses having a substantially rectangular cross section. Alternatively, one or more recesses may be configured as grooves.

The method may comprise cutting the sheet in a direction substantially transverse to the length of the sheet. Alternatively or in addition, the method may comprise cutting the sheet in direction substantially parallel to the length of the sheet.

The method may comprise feeding the sheet between the cutting support means and cutting the sheet in a substantially transverse direction to the direction of feed.

The method may comprise feeding the sheet between the cutting and support means and cutting the sheet in a substantially parallel direction to the direction of feed.

The method may comprise operating a cutting means which comprises one or more blades. The cutting means may be configured at a cutting mandrel. The cutting mandrel may be configured with axial cutting means which extend along a part of, or the whole of, or substantially the whole of the cutting mandrel. The cutting mandrel may be configured to have circumferential cutting means.

The method may comprise providing a support means configured as a support mandrel. The support mandrel may be configured to include one or more recesses which extend axially along a part of, or the whole or, or substantially the whole of the support mandrel, the method may comprise pushing a portion of the sheet into one or more recesses on the support mandrel.

The recesses on the support mandrel may extend around a part of, or the whole of, or substantially the whole of the circumference of the support mandrel.

The method may comprise feeding or positioning the sheet in a direction substantially perpendicular to the axes of the support mandrel the cutting mandrel cutting the sheet in a direction substantially transverse to the sheet length.

The method may comprise feeding or positioning the sheet in direction substantially perpendicular to the axes of the mandrels, to cut the sheet in a direction substantially parallel to the length thereof.

Preferably, the method comprises positioning the support mandrel and the cutting mandrel to provide a distance therebetween which is less than the thickness of the sheet to be cut, placing or feeding the sheet between the mandrels, compressing the sheet between the mandrels and forcing a portion of the sheet into the or each recess in the support mandrel, cutting the sheet at the sheet portions not in a recess providing partially joined pieces of sheet.

The method may comprise rotating mandrels, the mandrels may rotate at a similar speed in opposite directions.

The method may include support means and/or cutting means configured as a flat bed. The support flat bed may be provided with one or more recesses.

The method may comprise positioning the support flat bed and the cutting flat bed at a distance which is less than the thickness of the sheet to be cut, placing or feeding the sheet between the flat bed means, compressing the sheet and forcing one or more portions of the sheet into the or each recess on the support mandrel, cutting the sheet at portions put in the recess portions partially joined pieces of sheet.

Preferably the method according to this aspect of the invention may provide one or more pads which are suitable or use as a glass space pad to separate two sheets of glass. Alternatively, the pad may be sued as a marker.

Sheet material used with the method of this aspect of the invention made of foam.

According to another aspect the invention comprises a sheet comprising a plurality of pieces joined by one or more bridge portions, the bridge portions being arranged to break so as to separate a piece from the remainder of the sheet, the bridge portion(s) comprising a small fraction of the width of a piece-piece junction and a small fraction of the depth of adjacent bridge-connected pieces. A small fraction of the width may be 15% or less, 10% or less, 5% or less, or 1% or less. A small fraction of the depth may be 15% or less, 10% or less, 5% or less, or 1% or less.

Preferably the bridges are at a bottom surface of the sheet, preferably with a bridge surface that is co-planar with adjacent bottom surfaces of adjacent pieces.

Preferably the sheet/pieces is made of a single piece of material, preferably homogenous material, preferably resilient, preferably foam.

Preferably the cross-sectional area of contact of a bridge portion is significantly less than the cross-sectional area of facing edge surfaces of a piece-piece junction, preferably about 10% or less, 5% or less, 1% or less. In some embodiments about 95% or more, or 99% or more of the cross-sectional area at a piece-piece junction may have been cut through or otherwise be non-connected.

An embodiment of the first and fourth aspects of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a cutting apparatus according to the first aspect of the present invention;

Figure 2 is an end view of the apparatus of Figure 1;

Figure 3 is an enlarged schematic view of a strip being cut by the apparatus of Figures 1 and 2;

Figure 4 is a top plan view of a part of a strip according to the fourth aspect of the invention, and;

Figure 5 is a cross sectional view along line V-V of the strip of Figure 4.

Figures 1 and 2 show a cutting apparatus 1, which comprises support means in the form of a support mandrel 2 and cutting means provided on a cutting mandrel 3. The mandrels are capable of rotation. The support mandrel has three grooves 4 cut into it, which extend around the circumference of the mandrel. The grooves are equally spaced from one another, and each have a depth of 70µm and a width of 0.75 mm. The grooves are substantially rectangular in cross section as shown in Figure 3. The cutting means comprises four blades 7 which are attached to the cutting mandrel 3 and extend axially along the mandrel. The mandrels are aligned relative to each other and positioned such that the distance between the face of the support mandrel 2 and the tip of the blades 7 is less than the thickness of a strip to be cut.

The apparatus is particularly designed to cut a strip into two or more partially joined pads. In operation, a strip 8 is fed through the apparatus in a direction substantially perpendicular to the axes of the mandrels. The strip is fed through the apparatus by pulling means separate from the mandrels. The mandrels are rotated in opposite directions and the strip is fed between the mandrels such that a first longitudinal face 10 thereof is located over the grooves 4 (Figure 3). Due to the distance between the mandrels, the strip is compressed by the mandrels and the blades 7 and a portion 11 of the strip is pushed into each of the grooves 4. The blades 7 come into contact with a second face 12 of the strip, which cuts the strip into partially joined pads. The strip is cut in a transverse direction to the direction of travel of the strip. At each cut, the portions of the strip which are not contained in the grooves 4 are cut leaving the portions 11 of the strip uncut. Thus partially joined pads are formed in the strip.

These are joined by portions or bridges 11 (Figure 4). The height of the bridges is less than the thickness of the strip (Figure 5). When such a strip is used in a Lenhardt or other glass applicator machine or manually, a pad may be pulled away from and separated from the strip without undue difficulty and stretching of the strip.

Claims

A cutting apparatus (1) for cutting at least one sheet into two or more partially joined pieces comprising support means (2) and cutting means (3), the support means being provided with at least one recess (4), wherein, in use, the sheet (8) is positioned between the support means and the cutting means such that a force is applied to the sheet causing a portion thereof to be pushed into the or each recess and the sheet to be partially cut at the portion contained in the or each recess and to be wholly cut at a portion not contained in the or each recess.
An apparatus according to claim 1 wherein the cutting means (3) cuts the sheet (8) in a direction substantially transverse to the length of the sheet.
An apparatus according to claim 1 or claim 2 wherein the cutting means (3) cuts the sheet (8) in a direction substantially parallel to the length of the sheet.
An apparatus according to any preceding claim wherein the support means comprises a support mandrel.
An apparatus according to claim 4 wherein the support mandrel (2) is provided with one or more recesses (4) which extend around a part of, or the whole of, or substantially the whole of the circumference of the support mandrel (2).
An apparatus according to claim 4 wherein the support mandrel (2) is provided with one or more recesses (4) which extend axially along a part of, or the whole of, or substantially the whole of the support mandrel.
An apparatus according to any of claims 1 to 3 wherein the support means (2) comprises a flat bed, and the cutting means is provided on a flat bed, or on one or more plate-like elements or on a cutting mandrel.
An apparatus according to claim 7 wherein the support flat bed (2) is provided with one or more recesses (4).
A method of cutting a sheet into two or more partially joined pieces comprising positioning the sheet between a support means and a cutting means, applying force to the sheet to push a portion of the sheet into one or more recesses in the support means and operating the cutting means to bring the cutting means into contact with the sheet so as to cut the sheet only partially at a sheet portion or portions contained in the or each recess.
A method according to claim 9 which comprises applying one or more sheets (8) together with at least one backing sheet adjacent a longitudinal face of at least one sheet into the apparatus.
A method according to claim 10 which comprises covering or partly covering and/or adhering or partly adhering one or more backing sheets to at least one sheet using adhesive.
A method according to claim 10 or 11 which is arranged to leave the backing sheet uncut or partially uncut.
A method according to any of claims 10 to 12 which arranges the cutting means (3) to be a height above the support means (2) said height being roughly any of the following: more than the thickness of a backing sheet; equal to the thickness of a backing sheet; less than the thickness of a backing sheet; and zero height.
A method according to claims 9 to 13 wherein a sheet of material is cut in a direction substantially transverse to the length of the sheet.
A method according to claims 9 to 13 wherein the sheet material is cut in a direction substantially parallel to the length of the sheet.
A sheet (8) which comprises two or more partially joined pieces formed by the apparatus according to any of claims 1 to 8 or by the method according to any of claims 9 to 15.
A strip which comprises two or more partially joined strips formed by the apparatus according to any of claims 1 to 8 or by the method according to any of claims 9 to 15.