As mentioned above, the web splicer according to the present invention comprises a first roll supporter, a second roll supporter, a paster roll, a carriage, a carriage driving device and a pressing device.
The first roll supporter can be any structure which can rotatably support a first core having a first web wound therearound, a wide variety of such supporting structures being well known in the art. For example, a suitable roll supporter can be a pair of members each having a recess or an opening in which an end of the core is positioned, with bearings located between the respective ends of the core and the corresponding respective recesses or openings in the supporting structures.
Similarly, the second roll supporter can be any structure which can rotatably support a second core having a second web wound therearound, suitable structures including structures like those mentioned above in connection with the first roll supporter.
Preferably, the web splicer includes at least a second roll driver which, when actuated, causes the second roll to rotate, and which can be adjusted to cause the second roll to rotate at a desired rate of rotation.
The second roll (or “ready roll”) 14 constitutes a second web wound about a second core 15. The second core 15 is supported on a second roll supporter 16. The second core 1 has a prepared splice 37 attached to its exterior.
In
The term “web” as used herein means any form of ribbon material of any width, including but not limited to paper materials, paperboard materials, film materials, foil materials, non-woven materials, composite materials or any combination of such materials, which is to be unwound from a roll.
The cores in accordance with the present invention can be any structure capable of supporting the web wound thereon. A variety of core structures are well known to those of skill in the art, any of which can be employed in accordance with the present invention.
The second core is driven by any kind of driver, a variety of which are well known to those of skill in the art. For example,
In addition, if desired, the first roll can also be driven by any suitable means, as described above in connection with the second roll. Alternatively, the first web can be drawn solely by the drawing tension exerted by a downstream operation.
The web splicer in accordance with the present invention preferably also has devices for moving the respective first and second rolls. In a preferred aspect of the present invention, starting from the arrangement depicted in
Devices for moving the respective rolls can be any device capable of moving the cores and rolls, a wide variety of which are well known in the art. For example, a number of turret assemblies for moving multiple cores and rolls relative to one another are well known in the art. Similarly, core shaft loading and withdrawing devices may be employed as needed, such devices being well known in the art.
The paster roll can be any structure capable of reliably guiding the path of a web, e.g., any structure commonly used as an idler roll. A variety of such roll structures are well known to those of skill in the art, any of which can be employed as the paster roll in accordance with the present invention.
As mentioned above, the paster roll is rotatably mounted on the carriage, and is movable relative to the carriage. Referring to
The carriage in accordance with the present invention can be any rigid structure on which at least the paster roll can be movably mounted, and which can be driven from the first carriage position to the second carriage position by the carriage driving device. Preferably, the carriage is mounted such that it can readily move from the first carriage position to the second carriage position with minimum friction. Preferably, bearings are provided between the carriage and a frame on which the carriage is slidably mounted. Bearings 40 are schematically depicted in the each of the first, second and third embodiments shown in
The carriage driving device in accordance with the present invention can be any device capable of driving the carriage from the first carriage position to the second carriage position after an engage signal is fed to the carriage driving device. A wide variety of driving devices are well known to those of skill in the art, and any of such driving devices can be employed in the present invention.
Where a servo motor (or motor) is employed as the carriage driving device, such servo motor(s) can include any motor(s) which can provide the force needed to move the carriage from the first carriage position to the second carriage position in the desired relatively short time span.
Preferably, the carriage driving device is able also to readily move the carriage from the second carriage position back to the first carriage position after a disengage signal is fed to the carriage driving device, thereby moving the paster roll so that it no longer is abutting the second roll.
The web splicer depicted in
The web splicer depicted in
The web splicer depicted in
As mentioned above, the pressing device selectively causes force to be applied to the paster roll relative to the carriage, in order to apply a specific force between the paster roll and the second roll. As such, the force applied between the paster roll and the second roll can be specifically selected, and the magnitude of that force is independent of the force used to move the paster roll from the first location to the second location.
Any pressing device which is capable of applying a force to the paster roll relative to the carriage can be employed, a wide variety of such devices being well known to those of skill in the art. For example, a preferred pressing device is a pneumatic cylinder device, such devices being well known in the art. Alternatively, for example, a hydraulic cylinder device could readily be employed.
In the first, second and third embodiments, shown in
The web splicer according to the present invention preferably further comprises a web cutter for cutting the first web after splicing the first web to the second web. Any web cutter can be employed, and a variety of web cutters are well known to those skilled in the art. An example of a suitable web cutter is a web cut off knife which may be mounted within a shoe having a surface over which the web passes; when it is desired to cut the web, the cut off knife is extended above the surface of the shoe and into the path of the web, thereby severing the web.
In operation, the first web is unwound from the first roll (or “running roll”), the first web passing around and in contact with the paster roll and on to a downstream operation (e.g., a further processing operation or a winding operation) at a moving web speed. The degree of depletion of the first roll can be detected by any means, e.g., visually by a human operator or automatically by any of a variety of well known apparatuses for sensing when a roll has reduced to a particular diameter, e.g., a photo detect eye. As the first roll is nearing the degree of depletion at which the roll change is to be effected, preferably, the second roll is positioned adjacent to the paster roll and is brought up to a circumferential speed which corresponds (at least substantially, e.g., to within 80-120%) to the moving web speed. In order to cause the circumferential speed of the second roll to correspond, at least substantially, with the moving web speed, the moving web speed can be detected in any manner (suitable moving web speed detection techniques and apparatus being well known to those of skill in the art), and the circumferential speed of the second roll can be monitored and compared with the detected moving web speed. Based on the results of the comparison between the detected moving web speed and the detected circumferential speed of the second web, adjustments can be made to increase, decrease or maintain the circumferential speed of the second web. Techniques and apparatus for performing such operations are well known in the art. For example, the circumferential speed of the second roll can be automatically calculated by measuring or detecting the diameter of the second roll, and either setting the second roll driver to a specific RPM value or detecting the rate of rotation of the second roll and adjusting the power to the second driver to bring the rate of rotation of the second roll to a specific RPM value. Alternatively, as is well known in the art, sonics can be used to measure the velocity of the edge of the roll. Likewise, the speed of the moving web can be monitored accurately, e.g., by a tachometer or shaft encoder responding to the surface speed or angular velocity of a fixed diameter guide roller around which the moving web is trained. The surface speed of a web roll may also be determined by measuring the angular velocity of the roll using a shaft encoder operatively connected to an element supporting the web roll. Multiplying that angular velocity and the radius of the roll yields the surface speed of the roll.
When the first roll reaches the degree of depletion at which the roll change is to be effected, e.g., when the first roll is nearly depleted, an engage signal is sent to the carriage driving device, as a result of which the carriage driving device causes the carriage to move from the first carriage position to the second carriage position, whereby the paster roll is moved to a position where it abuts the second roll. Preferably, the movement of the carriage from the first carriage position to the second carriage position is extremely rapid, e.g., the time for such movement is on the order of from about 15 milliseconds to about 150 milliseconds. In general, for smaller ready roll diameters and more rapid web speeds, a shorter time for movement of the carriage from the first carriage position to the second carriage position is desired. Greater horsepower (for the carriage driving device) is required, where the weight of the carriage is larger (e.g., where wider rolls are being spliced), to move the carriage from the first carriage position to the second carriage position.
A preferred further aspect of the present invention is a high degree of repeatability, i.e., small variance of the time for movement of the carriage from the first carriage position to the second carriage position. For example, it is preferred that the time for movement of the carriage from the first carriage position to the second carriage position on one occasion differs not more than 10%, preferably not more than 5%, more preferably not more than 2%, from the time for movement of the carriage from the first carriage position to the second carriage position on any other occasion.
Another preferred aspect of the present invention is the capability of automatic or simple manual adjustment of the web splicer of the present invention to vary the length of time for movement of the carriage from the first carriage position to the second carriage position. For example, the web splicer of the present invention can include a servo motor (functioning as the carriage driving device) which is adjustable to select different power settings so as to vary the time for movement of the carriage from the first carriage position to the second carriage position.
Preferably, by the time the carriage reaches the second carriage position, the pressing device has already been activated (e.g., in the case of a cylinder, the cylinder has been pressurized) to apply force to the paster roll relative to said carriage, such force pressing the paster roll, and the first web which is sandwiched between the paster roll and the second roll, against the second roll. More preferably, the pressing device is activated prior to the time that the engage signal is sent to the carriage driving device, so that when the carriage is moved to the second carriage position, the pressing device is exerting the desired force on the paster roll relative to the carriage (i.e., there is no delay while, e.g., the pressure within the cylinder builds up).
The second roll preferably has at least one prepared splice, i.e., a region on the second roll which creates the adhesion between the first web and the second web which holds the respective webs together and creates the splice. A variety of prepared splices are well known in the art. For example, a prepared splice can include a region of adhesive or a strip of double-sticky tape.
Preferably, the carriage is moved into the second carriage position to bring the paster roll into contact with the second roll at a contact location when the prepared splice on the second roll is between 90 degrees and 270 degrees of rotation (preferably about 180 degrees) away from the contact location (i.e., such that the prepared splice rotates between one quarter and three quarters (preferably about one half) of a rotation of the second roll, after the paster roll comes into contact with the second roll, before the prepared splice passes through the nip between the paster roll and the second roll). Providing at least one quarter of a revolution after the paster roll comes into contact with the second roll and before the prepared splice passes through the nip helps to ensure that the paster roll is positively in contact with the second roll before the splice reaches the nip, and allows sufficient settle out time should there be any bounce of the paster roll off the second roll, thereby making the splice more reliable. Providing at least one quarter of a revolution after the previous occurrence of the splice passing through the nip before the paster roll comes into contact with the second roll helps to ensure that the splice does not prematurely engage the first web, and helps to ensure that any material which holds the leading edge of the second web on the second roll does not prematurely disengage and cause the second web to begin to unwind and fly away from the second roll before the second web is spliced to the first web. One example of a type of material which is well known to those of skill in the art for holding the leading edge of a web on its roll is a tear tab (or nose tab), which is essentially a length of tape which is stuck to both the leading edge of the web and the adjacent exposed section of the web which is just less than one web revolution from the leading edge. Typically, especially with wider rolls, a plurality of tear tabs are employed, the number of tear tabs depending on the width of the roll (more tear tabs for wider rolls), the circumferential speed of the roll (more tear tabs for higher speeds) and the diameter of the roll (more tear tabs for smaller diameters). Where one or more tear tabs are employed, after the second web is spliced to the first web, the tear tabs will pull away from the adjacent exposed section of the web as the second web is pulled away from the second roll along the path that the first web has been following.
In order to time the movement of the carriage relative to the location of the prepared splice (and thus also relative to the time before the prepared splice passes through the contact location), the web splicer preferably further includes a detector which detects occurrences of the splice region on the second roll passing a detection location or region, as well as a timing device for creating a signal at a time where (1) the ratio of (i) the time since the last occurrence of the prepared splice passing through the nip and (ii) the time interval between occurrences of the prepared splice passing through the nip is equal to (2) one revolution minus the fraction of a revolution (e.g., one quarter or three quarters, as mentioned above) that is desired for the second roll to rotate after the paster roll comes into contact with the second roll and before the prepared splice passes through the nip. A variety of such detectors are well known to those of skill in the art. For example, the detector can be a photo detect eye (e.g., mounted on a frame of the web splicer, which can detect a mark placed on the second roll adjacent to the splice). A preferred example of a timing device is a device which includes a high-speed pulse generator and a high-speed pulse counter (e.g., mounted on the spindle). With such a timing device and detector, the web splicer can be operated whereby the pulse counter detects a pulse per revolution value, i.e., the number of pulses between occurrences of the splice region passing the detection location or region, and subsequently a signal is created when the number of pulses since the most recent occurrence of the splice region passing the detection location or region reaches a specific fraction of the pulse per revolution value. Preferably, the number of pulses at which the signal is sent is adjusted to account for the delay time between the creation of the engage signal and the time the carriage reaches the second carriage position (which delay time is, as mentioned above, preferably on the order of from about 15 milliseconds to about 150 milliseconds; and such delay time can readily be tested, taken to be a constant, and calibrated into the system). For example, where it is desired that the second roll rotate between one quarter of a revolution and three quarters of a revolution after the carriage reaches the second carriage position by the time the prepared splice reaches the nip between the second roll and the paster roll, the number of pulses is preferably between (1) one quarter of the pulse per revolution value plus the number of pulses corresponding to the delay time, and (2) three quarters of the pulse per revolution value plus the number of pulses corresponding to the delay time. Thus, before creating the engage signal, the web splicer preferably waits a number of pulses equal to the desired fraction of a complete revolution to be traveled times the number of pulses in a complete revolution, minus the number of pulses corresponding to the delay time, after the splice passes the detection location or region.
Preferably, the timing of movement of the carriage to the second carriage position is controlled with a programmable logic controller assigned to the carriage driving device. For example, the programmable logic controller preferably determines the precise timing for sending a signal to the carriage driving device based on (1) the time for the second roll to complete an entire revolution, (2) the fraction of a revolution to be traveled after the paster roll comes into contact with the second roll until the prepared splice passes through the nip, and (3) the delay time (i.e., as mentioned above, the time between the issuance of a signal and the time the carriage reaches the second carriage position).
In addition, the timing of actuating the web cutter to cut the first web is preferably timed such that the tail (i.e., the length of the first web which extends downstream of the splice between the first web and the second web) is relatively short and highly repeatable. It is preferred that the tail be less than one circumference of the first roll (as of the time of the splice). Preferably, however, in any event, the tail is not less than six inches in length (regardless of roll diameter). Preferably, the timing of actuation of the web cutter is controlled, relative to (1) the time that an engage signal is given to the carriage driving device, (2) the time between such engage signal and the splice region passing through the contact location, (3) the desired tail length, (4) the web speed of the first web, and (5) the cutter delay between the time that the web cutter receives a signal to actuate the web cutter and the time that the web cutter is in position to cut the web, with a programmable logic controller assigned to the web cutter, the web cutter having its own servo motor or pneumatic air device for actuating the web cutter upon receiving a signal from the programmable logic controller. For instance, as a representative example of a cutter delay, where the web cutter is a servo fired knife, the cutter delay can be, for example, on the order of about 15 msec (where the web cutter is a pneumatic knife, the cutter delay can be, for example, on the order of about 200 msec).
After a desired length of time (preferably set or selected based on the desired tail length) has passed following the splice passing through the nip between the second roll and the paster roll, preferably a disengage signal is sent to the carriage driving device. Upon receiving the disengage signal, the carriage driving device moves the carriage from the second carriage position back to the first carriage position, thereby moving the paster roll from the second location, where it is abutting the second roll back to the first location, where it is not abutting the second roll.
Any two or more structural parts of the web splicers described above can be integrated. Any structural part of the web splicers described above can be provided in two or more parts, which can be held together, if necessary or desired.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US04/23812 | 7/23/2004 | WO | 00 | 7/13/2007 |
Number | Date | Country | |
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60490182 | Jul 2003 | US |