Sign forming apparatus, method and die for use therein

Claim 2

In sign forming apparatus for reproducing characters or patterns in a strip of thermoplastic sheet material, a set of dies each having a planar configuration with a raised portion on one face conforming to a character or pattern to be reproduced, a die heating station including heating means for heating a die and further including means for slidably receiving and supporting the die with said one face thereof facing in a predetermined direction and with the opposite face thereof positioned adjacent to said heating means, a cutting pad for supporting the strip of thermoplastic sheet material opposite to said one face of a die supported by said die heating station, means for moving said die heating station between a first, ready position at which a die supported thereby is spaced away from said cutting pad and a second, cutting position at which the die supported thereby is positioned in engagement with said cutting pad to thereby cause the heated die to thermally cut the character or pattern defined on said one face thereof into the strip of thermoplastic sheet material interposed between the heated die and the cutting pad, and a die cooling station including means for slidably receiving, supporting, and cooling a heated die from said die heating station, said die cooling station being aligned to receive a heated die from said die heating station when the latter is in said first, ready position.

Claim 3

Sign forming apparatus as in claim 1 wherein each die comprises a flat plate of relatively thin cross section made of a high thermal-conductivity, low heat-capacity material, a raised bulb portion disposed on said plate and integrally joined thereto, said raised bulb portion linearly conforming to the outline of the character or pattern to be reproduced by the die and being rounded in cross section, a cutting bead formed on said raised bulb portion and defining an outline of the character or pattern to be reproduced by the die, said cutting bead being integrally formed with said raised bulb portion and symmetrically disposed on that side of said raised bulb portion away from said plate, said raised bulb portion serving as a heat sink for supplying heat to said cutting bead so that as said cutting bead is pressed into contact with the strip of thermoplastic sheet material said cutting bead is supplied with adequate heat to thermally cut through the thermoplastic material.

Claim 4

Sign forming apparatus as in claim 1 further including indicia means disposed on said opposite face of each die for indicating the correct direction of insertion of the die into the sign forming apparatus.

Claim 5

Sign forming apparatus as in claim 1 further including a spacing scale marked on the sign forming apparatus alongside the path of the strip of thermoplastic sheet material, and indicia means carried on each die for indicating its proper character half width and character spacing half width in the same values as said spacing scale.

Claim 6

Sign forming apparatus as in claim 1 further including a notch forMed on one side of each die, and means forming a detent mechanism on said die heating station for engaging said notch whereby the position of a die can be felt by an operator when inserting a die into the sign forming apparatus.

Claim 7

In sign forming apparatus, means forming a framework comprising a pair of side plates including upstanding portions, a base plate and means for connecting said base plate and said side plates into a self-supporting structure, means, including a cutting pad carried on said base plate, forming a carrier plane for passing a thermoplastic material through the sign forming apparatus, means forming guide means vertically arranged between the upstanding portions of said side plates and interconnected therebetween, a die heating station carried on said guide means and including a heating plate, a heater and a thermostat for controlling the amount of heat supplied to said heating plate within a predetermined temperature range, and means secured to said heating plate for supporting said die heating station for sliding movement upwardly and downwardly on said guide means, means for moving said die heating station between a raised, ready position and a lower, cutting position in which a die carried on the underside of said heating plate is proximate said cutting pad and cuts through the thermoplastic material interposed between the die and said cutting pad, and a die cooling station including a heat sink having cooling fins thereon and further including fan means for moving air past said cooling fins to cool them, said die cooling station being mounted on said framework such that it is positioned to receive a die from said die heating station when the latter is in its raised, ready position.

Claim 8

In sign forming apparatus, means forming a framework comprising a pair of side plates including upstanding portions, a base plate and means for connecting said base plate and said side plates into a self-supporting structure, means, including a cutting pad carried on said base plate, forming a carrier plane for passing a thermoplastic material through the sign forming apparatus, means forming guide means vertically arranged between the upstanding portions of said side plates and interconnected therebetween, a die heating station carried on said guide means and including a heating plate, a heater and a thermostat for controlling the amount of heat supplied to said heating plate within a predetermined temperature range, and means secured to said heating plate for supporting said die heating station for sliding movement upwardly and downwardly on said guide means, means for moving said die heating station between a raised, ready position and a lower, cutting position in which a die carried on the underside of said heating plate is proximate said cutting pad and cuts through the thermoplastic material interposed between the die and said cutting pad, and a die cooling station including a heat sink having cooling fins thereon and further including fan means for moving air past said cooling fins to cool them, said die cooling station being mounted on said framework such that it is positioned to receive a die from said die heating station when the latter is in its raised, ready position.

Claim 9

Sign forming apparatus as in claim 6 wherein said means for moving said die heating station includes a cylindrical cam eccentrically mounted on said guide means, said die heating station includes first follower means disposed above said cam for raising said die heating station when a lobe defined by said cam is in an upper position, and second follower means is mounted below said cam for pressing said die heating station into thermal cutting relationship against the thermoplastic material when said cam is rotated to a lowermost position.

Claim 10

Sign forming apparatus as in claim 7 further including means for precisely adjusting the position of said second follower means to control the precise height of said die heating station in its lower, cutting position.

Claim 11

Sign forming apparatus as in claim 6 further including clamp rails positioned on each side of the thermoplastic material and overlying said cutting pad, means for normally urging said clamp rails into engagement with the edges of the thermoplastic material, and means associated with said clamp rails and said die heating station for disengaging said clamp rails from the thermoplastic material when said die heating station is in its raised, ready position.

Claim 12

In sign forming apparatus for reproducing characters or patterns in a strip of thermoplastic sheet material, a set of dies each having a planar configuration with a raised portion on one face conforming to the character or pattern to be reproduced and each being made of a material having a high thermal conductivity and a low total heat capacity so that it may be readily heated and cooled, a die heating station including die heating means for heating a die and further including means for slidably receiving and supporting the die with said one face thereof facing in a predetermined direction and with the opposite face thereof positioned adjacent to said die heating means, said die heating means being made of a material having a high thermal conductivity and a high total heat capacity so that its temperature is not markedly changed by heating a die applied thereto, a cutting pad for supporting the strip of thermoplastic sheet material opposite said one face of a die supported by said die heating station, means for moving said die heating station betwEen a first, ready position spaced away from said cutting pad and a second, cutting position in engagement with said cutting pad thereby causing a heated die supported by said die heating station to thermally cut the character or pattern defined on said one face of the heated die into the strip of thermoplastic sheet material interposed between the heated die and said cutting pad, and a die cooling station including means for slidably receiving, supporting, and cooling a heated die from said die heating station, said die cooling station being aligned to receive the heated die from said die heating station when the latter is in said first, ready position.

Claim 13

In sign forming apparatus for reproducing characters or patterns in a strip of thermoplastic sheet material, a set of dies each having a planar configuration with a raised portion on one face conforming to the character or pattern to be reproduced and each being made of a material having a high thermal conductivity and a low total heat capacity so that it may be readily heated and cooled, a die heating station including die heating means for heating a die and further including means for slidably receiving and supporting the die with said one face thereof facing in a predetermined direction and with the opposite face thereof positioned adjacent to said die heating means, said die heating means being made of a material having a high thermal conductivity and a high total heat capacity so that its temperature is not markedly changed by heating a die applied thereto, a cutting pad for supporting the strip of thermoplastic sheet material opposite said one face of a die supported by said die heating station, means for moving said die heating station betwEen a first, ready position spaced away from said cutting pad and a second, cutting position in engagement with said cutting pad thereby causing a heated die supported by said die heating station to thermally cut the character or pattern defined on said one face of the heated die into the strip of thermoplastic sheet material interposed between the heated die and said cutting pad, and a die cooling station including means for slidably receiving, supporting, and cooling a heated die from said die heating station, said die cooling station being aligned to receive the heated die from said die heating station when the latter is in said first, ready position.

Claim 14

In sign forming apparatus for forming signs in a strip of thermoplastic sheet material by using a set of dies each of which has a planar configuration and a raised portion on one face thereof conforming to a character or pattern to be reproduced, a die heating station including means for slidably receiving, supporting, and heating a die with said one face thereof facing towards a cutting pad for supporting the strip of thermoplastic sheet material, means for moving said die heating station into engagement with said cutting pad to thereby cause a heated die supported by said die heating station to thermally cut the character or pattern defined on said one face thereof into the strip of thermoplastic sheet material interposed between the heated die and the cutting pad, and a die cooling station for receiving and cooling a heated die from said die heating station, said die cooling and heating stations including means for removing any die positioned in said die cooling station, remotely transferring any die positioned in said die heating station to said die cooling station, and feeding a die into said die heating station, whereby a plurality of dies may be successively employed to thermally cut the characters or patterns of a sign into the strip of thermoplastic sheet material by cooling each heated die immediately after it is employed to thermally cut a character or pattern of the sign while the next die is heated and employed to thermally cut the next character or pattern of the sign, said sign forming apparatus further including spacing means for aiding the operator to advance the strip of thermoplastic sheet material by an amount equal to the appropriate sum of the half widths of the characters or patterns defined on said one face of each of the dies in said die heating and cooling stations and of the half widths of appropriate inter-character or pattern spacings for each of those characters or patterns to form a pre-spaced segment of a sign.

Claim 15

In sign forming apparatus for forming signs in a strip of thermoplastic sheet material by using a set of dies each of which has a planar configuration and a raised portion on one face thereof conforming to a character or pattern to be reproduced, a die heating station including means for slidably receiving, supporting, and heating a die with said one face thereof facing towards a cutting pad for supporting the strip of thermoplastic sheet material, means for moving said die heating station into engagement with said cutting pad to thereby cause a heated die supported by said die heating station to thermally cut the character or pattern defined on said one face thereof into the strip of thermoplastic sheet material interposed between the heated die and the cutting pad, and a die cooling station for receiving and cooling a heated die from said die heating station, said die cooling and heating stations including means for removing any die positioned in said die cooling station, remotely transferring any die positioned in said die heating station to said die cooling station, and feeding a die into said die heating station, whereby a plurality of dies may be successively employed to thermally cut the characters or patterns of a sign into the strip of thermoplastic sheet material by cooling each heated die immediately after it is employed to thermally cut a character or pattern of the sign while the next die is heated and employed to thermally cut the next character or pattern of the sign, said sign forming apparatus further including spacing means for aiding the operator to advance the strip of thermoplastic sheet material by an amount equal to the appropriate sum of the half widths of the characters or patterns defined on said one face of each of the dies in said die heating and cooling stations and of the half widths of appropriate inter-character or pattern spacings for each of those characters or patterns to form a pre-spaced segment of a sign.

Claim 16

Sign forming apparatus as in claim 11 wherein said spacing means includes a fiducial mark on the sign forming apparatus, and a template having at least one indicium thereon corresponding to the next character or pattern to be thermally cut, whereby said template may be positioned over the strip of thermoplastic sheet material such that the indicium thereon is appropriately positioned relative to the preceding character or pattern thermally cut into the strip of thermoplastic sheet material, the strip of thermoplastic sheet material may then be marked to indicate the distance from said fiducial mark on the sign forming apparatus to the center of said cutting pad, and the strip of thermoplastic sheet material may then be advanced so that the mark thereon coincides with said fiducial mark.

Claim 17

Sign forming apparatus for forming characters in a strip of thermoplastic material, said apparatus comprising a die heating station for slidably receiving and heating a die having a planar base with a raised portion defining a character to be formed and facing the strip of thermoplastic material, a platen for supporting the strip of thermoplastic material opposite the raised portion of the die, means for moving the die heating station between a ready position spaced away from the platen to receive the die and a cutting position spaced closer to the platen to bring the die into contact with The strip of thermoplastic material and thermally die cut the character defined by the raised portion of the die in the strip of thermoplastic material, and a die cooling station for slidably receiving the die from the die heating station when the die heating station is in the ready position and for cooling the die.

Claim 18

Sign forming apparatus for forming characters in a strip of thermoplastic material, said apparatus comprising a die heating station for slidably receiving and heating a die having a planar base with a raised portion defining a character to be formed and facing the strip of thermoplastic material, a platen for supporting the strip of thermoplastic material opposite the raised portion of the die, means for moving the die heating station between a ready position spaced away from the platen to receive the die and a cutting position spaced closer to the platen to bring the die into contact with The strip of thermoplastic material and thermally die cut the character defined by the raised portion of the die in the strip of thermoplastic material, and a die cooling station for slidably receiving the die from the die heating station when the die heating station is in the ready position and for cooling the die.

Claim 19

Sign forming apparatus as in claim 13 wherein the planar base of the die comprises a flat plate of thinner cross section than the raised portion of the die, and the raised portion of the die comprises a bulb of rounded cross section integrally formed on this plate and a smaller cutting bead integrally formed on the bulb, the bulb serving as a heat sink for supplying the bead with adequate heat to thermally cut through the thermoplastic material.

Claim 20

Sign forming apparatus as in claim 13 wherein the die includes an indicium for indicating the correct direction of insertion of the die into the die heating station.

Claim 21

Sign forming apparatus as in claim 13 wherein a spacing scale is provided on the apparatus along the path of the strip of thermoplastic material, and an indicium is provided on the die to indicate the half width of the character defined thereon and a spacing therefor in the same units as the spacing scale.

Claim 22

Sign forming apparatus as in claim 13 wherein a notch is formed on one side of the die, and a detent mechanism is provided on the die heating station to engage this notch when the die is properly positioned in the die heating station.

Claim 23

Sign forming apparatus as in claim 13 wherein the die heating station includes a heating plate, a heater, and a thermostat for controlling the amount of heat supplied to the heating plate within a predetermined temperature range, and wherein the die cooling station includes a heat sink with cooling fins and a fan for moving air past these cooling fins to cool them.

Claim 24

Sign forming apparatus as in claim 18 wherein the heating plate is made of a material having a thermal conductivity and a total heat capacity such that its temperature is not markedly changed by heating a die applied thereto, and the die is made of a material having a thermal conductivity and a heat capacity such that it may be readily heated by the heating plate and cooled by the heat sink.

Claim 25

Sign forming apparatus as in claim 13 wherein the means for moving the die heating station includes an eccentrically-mounted cylindrical cam, and the die heating station includes first follower means disposed above the cam to raise the die heating station when a lobe of the cam is in an upper position and second follower means disposed below the cam to limit the downward stroke of the die heating station toward the strip of thermoplastic material supported on the platen and thereby determine the cutting position.

Claim 26

Sign forming apparatus as in claim 20 including means for precisely adjusting the position of the second follower means to adjust the cutting position of the die heating station.

Claim 27

Sign forming apparatus as in claim 13 including clamp rails overlying each side of the platen and the sheet of thermoplastic material supported thereon, means for normally urging the clamp rails into engagement with the edges of the strip of thermoplastic material, and means for disengaging the clamp rails from the strip of thermoplastic material when the die heating station is in the ready position.

Claim 28

Sign forming apparatus as in claim 13 wherein the die received by the die heating station is transferred to the die cooling station after the character defined by that die has been thermally die cut, another similar die is then fed to the die heating station, the strip of thermoplastic material is advanced by an amount equal to the sum of the half widths of the characters supported at the die cooling and heating stations and of the half widths of the desired spacing between each of those characters and its neighbor, the character defined by the die then supported at the die heating station is thereupon thermally die cut, and the foregoiNg steps are repeated to form a pre-spaced sign or a portion thereof.

Claim 29

Sign forming apparatus as in claim 13 including a template having at least one indicia thereon corresponding to the distance between the center of the next character to be formed, when the die on which that character is defined is at the die heating station, and a reference mark provided on the apparatus adjacent to the strip of thermoplastic material.

Claim 30

Sign forming apparatus as in claim 1 wherein the die comprises a plate of thermally conductive material, a raised bulb portion of rounded cross section integrally formed on this plate to indefine a character thereon, and a cutting bead of smaller cross section integrally and symmetrically formed on this bulb portion, the bulb portion serving as a heat sink for supplying the cutting bead with heat to thermally die cut through the sheet of thermoplastic material.