DE9418731U1 - Cutting arrangement with a circuit for detecting a false cut - Google Patents

Description

22 November 1994 Ranpak Corporation R 21Ö22 G/Kk/mj/cp

6hm

Cutting arrangement with a circuit for detecting

a miscut

This invention relates generally to a cutting assembly having a cutting error detection circuit. More particularly, this invention relates to a cutting error detection circuit that detects when a cutting device has failed to complete a cutting process within a prescribed period of time. More specifically, the cutting error detection circuit is used in a dampening converter machine and serves to turn on an indicator light to provide a visual error indication when a cutting error has occurred and to cut off power to a motor driving the cutting device to protect the motor and other components of the machine when a cutting error has occurred.

In the process of shipping a good from one place to another, a protective packaging material is typically placed in a shipping crate or box to fill any empty spaces and/or cushion the good during the shipping process. Some conventional, commonly used protective packaging materials are plastic foam beads and plastic bubble packs. While these conventional plastic materials serve adequately as cushioning products, they are not without disadvantages. For example, one disadvantage of plastic bubble coating is that it

usually contains a polyvinylidene chloride coating. This coating prevents the plastic layer from being safely incinerated, often causing disposal difficulties. In addition, both the plastic foam pellets and the plastic bubble packs have a tendency to generate electrostatic charge that attracts dust from the surrounding packaging area. Sometimes these plastic materials also generate a significant amount of packaging "lint" themselves. Such dust and lint particles are generally undesirable and can even be destructive to sensitive goods such as electronic or medical devices.

Perhaps the most serious disadvantage of plastic bubble wrap and/or plastic foam pellets is their impact on our environment. These plastic packaging materials are simply not

is biodegradable and therefore cannot avoid further aggravating the waste disposal problem that is already critical for our planet. The lack of biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility.

These and other disadvantages of traditional plastic packaging materials have made protective paper packaging a very popular alternative. Paper is biodegradable, recyclable and renewable; making it an environmentally responsible choice for conscious industries. Additionally, paper can be safely incinerated by recipients of the product. Furthermore, protective paper packaging is ideal for goods that are sensitive to particles, as its clean, dust-free surface is resistant to static cling.

While paper in web form could potentially be used as a protective packaging material, it is usually preferred to convert the paper webs into a cushion-like, relatively low density, padding product. This conversion can be accomplished by a padding converter machine such as those disclosed in U.S. Patent Application Nos. 08/066,337; 07/840,306; 07/712,203 (now Patent No. 5,123,889); and 07/592,572 (all of which are assigned to the assignee of the present invention). Such a padding converter machine converts web-like stock material such as paper

&iacgr;&ogr; in multi-ply form, into cut sections of a relatively low density cushioning product. The stock material may consist of three stacked sheets or layers of biodegradable, recyclable and reusable 30-pound kraft paper rolled into a hollow, cylindrical tube.

A 30-inch roll of this paper, approximately 450 feet long, weighs about 35 pounds and provides cushioning equal to about four 15-cubic-foot bags of synthetic foam granules, while requiring less than one-thirtieth of the storage space.

More specifically, the machine converts the stock material into a continuous, unjointed strip having lateral pillow-like sections separated by a thin, central band. This strip is joined or embossed along the central band to form an embossed strip which is cut into sections of a desired length. These cut sections each comprise lateral pillow-like sections separated by a thin, central band and provide an excellent, relatively low density, cushion-like product which can be used in place of conventional protective plastic packaging material.

· · ■

The dampening converter machine disclosed in the above-referenced applications includes a frame having an upstream and a downstream end (the terms "upstream" and "downstream" in this context refer to the direction of flow of the stock material through the machine). The frame is formed from a base plate, an upstream end plate and a downstream end plate. The downstream end plate is generally rectangular and includes a relatively narrow rectangular discharge opening. The frame also includes a box-like extension removably attached to a downstream portion of the base plate.

The machine further includes a stock supply assembly, a forming assembly, a gear assembly, a cutting assembly and a recutting enforcing assembly, all mounted on the machine frame. During operation of the machine, the stock supply assembly supplies stock material to the forming assembly. The forming assembly causes the lateral edges of the web-like stock material to curl inward to form lateral pillow-like portions of the continuous strip. The gear assembly draws the stock material through the machine and also embosses the central band of the continuous strip to form the embossed strip. The embossed strip passes downstream from the gear assembly and through the outlet opening in the end plate. The cutting assembly, mounted on the downstream side of the end plate, cuts the

embossed strips into sections of a desired length. These cut sections then run through the post-cutting constraining arrangement.

The post-cutting constraining assembly is located downstream of the cutting assembly and is mounted on the box-like extension. The

The post-cut constraining assembly is basically funnel-shaped and is positioned so that its inlet is aligned with the outlet port of the end plate. A cut section is urged or pushed downstream through the post-cut constraining assembly by the approaching embossed strip. As the cut section passes through the post-cut constraining assembly, it is circumferentially constrained to improve its buffering quality.

In the above applications, the cutting assembly includes a stationary blade and a moving blade, both strategically positioned relative to the discharge port. During operation of the cutting assembly, the moving blade travels between a rest position and a cutting position. More specifically, the moving blade travels through a cycle, making a cutting stroke and a return stroke to the rest position. During the cutting stroke, the moving blade travels across the discharge port and interacts with the stationary blade. For example, the moving blade may interact with the stationary blade in a "guillotine" manner, or alternatively may interact with the stationary blade in a "scissors" manner.

Applicants believe that the cutting assemblies disclosed in the above-referenced applications perform their cutting functions adequately. Nevertheless, applicants believe that in certain situations the cutting assembly may fail to adequately cut the embossed strip because the embossed strip has become trapped between the moving blade and the stationary blade, for example. It would be desirable to provide a cutting device and circuitry that provides a fault indication to indicate to an operator that the

Cutting assembly has failed to cut the embossed strip, and to provide a cutting assembly and circuit that prevents excessive wear of the machine during a miscut or cutting error.

The present invention provides a cutting apparatus having a cutting error detection circuit that uses a pulse generator to determine the amount of time the machine is performing a cutting operation. If the time exceeds a predetermined amount of time suitable for a proper cutting operation, an error indicator lamp is illuminated and/or the cutting operation is interrupted.

According to one aspect of the present invention, a cutting device includes a blade movable between a first and a second position, the blade cooperating with another surface to cut a material, a motor for moving the blade between the first and second positions, a sensor for detecting when the blade is in the first position, a pulser for regulating the duration the blade is not in the first position; and a relay for interrupting power to the motor when the duration the blade is not in the first position exceeds a predetermined duration. The cutting device may also include a relay operative to illuminate an error indicator lamp when a cutting error has occurred.

According to another aspect of the invention, the cutting error detection circuit comprises a power supply device for supplying a motor with electrical energy to cause the blade to move between a first position and a second position.

tion, a detector for detecting when the blade is away from the first position, a pulse generator for setting the duration of time the blade is not in the first position, and a relay for cutting off power to the motor when the duration of time the blade is not in the first position exceeds a predetermined time. The circuit preferably illuminates an error indicator lamp when a cutting error has occurred.

&iacgr;&ogr; In general, the invention includes the foregoing and other features particularly described hereinafter and pointed out in the claims, the following description and the accompanying drawings set forth in detail a specific illustrated embodiment of the invention, which is but one of several ways in which the principles of the invention may be applied.

In the attached drawing:

Fig. 1 is a plan view of an exemplary damping converter machine in which the apparatus and functions of the present invention may be employed;

Fig. 2 is a view of the cutting assembly of the damping converter machine of Fig. 1;

Fig. 3 is a view of the cutting assembly of Fig. 2 shown in a partially cut position; and

Figures 4A to 4C are schematic diagrams of a cutting error detection circuit according to the present invention.

Referring in detail to the drawings and initially to Figures 1-3, there is shown an exemplary machine 10 in which the present invention may be used. The exemplary machine 10 depicted in Figures 1-3 is a cushioning converter machine that converts a number of plies of recyclable and reusable kraft paper into a continuous, unbonded strip having lateral, cushion-like portions separated by a thin central band. This material is used as an environmentally conscious, protective packaging material typically used during shipping.

is The machine 10 includes a frame, generally designated 12, having an upstream end 14 and a downstream end 16. The kraft paper from which the packaging material is made is unrolled from a roll (not shown) near the upstream end 14 of the frame 12, passes through the machine 10 and exits at the downstream end 16. The frame 12 is formed of a base plate 18 and two end plates 20 and 22. A generally rectangular outlet opening 24 in the end plate 22 (see Figures 2 and 3) allows the converted pad to exit the frame 12. The machine 10 further includes a supply supply assembly (not shown), a forming assembly 26, a feed gear assembly 28 driven by a feed motor 30 through a motion transmission assembly 32, a cutting assembly 34 driven by a cutting motor 36 through a solenoid and clutch assembly 38; all mounted on the frame 12. A post-cutting force assembly 40 is located

downstream of the cutting assembly 34 and is mounted on a removable, box-like extension 42 on the downstream side 16 of the frame 12.

In operation of the machine 10, stock supply material is fed to the forming assembly 26 where it enters the forming member 44 and the converging chute 46. The forming assembly 26 causes the lateral edges of the web-like stock material to roll inward to form lateral, pillow-like portions of the continuous strip stock material. The feed gear assembly 28 performs two functions in operation of the machine 10.

One function is a "feeding" function in which the material is pulled by the pinching of two cooperating and opposing gears of the gear assembly 28. Thus, the feed assembly 28 is the mechanism that pulls the stock material from a supply roll through the forming members 44 and converging chute 46 of the forming assembly 26, over the guide board 48 and through the rectangular opening 24 in the end plate 22. The second function performed by the feed gear assembly 28 is an "embossing" or "joining" function. Specifically, the feed gear assembly 28 joins the continuous strip by means of two opposing gears that emboss its central band running therethrough to form the embossed strip 50 shown in Figures 2 and 3. As the embossed strip 50 passes downstream from the feed gear assembly 28 through the opening 24, it passes through the cutting assembly 34 which cuts the strip into pieces of a desired length. These cut pieces 50 then pass

by the post-cutting arrangement 40, which has a tapered

section 52 and a rectangular tunnel section 54. The embossed strip 50 then emerges from the rectangular tunnel section 54 where an operator can remove the embossed strip from the machine 10.
s

The cutting assembly 34 is better shown in Figures 2 and 3. The cutting assembly 34 includes a stationary blade 56 and a movable blade 58, both strategically positioned with respect to the outlet opening 24. The blades 56 and 58 are the actual "cutting elements" of the cutting assembly 34 and cooperate in a scissor-like manner to cut the embossed strip 50 into cut pieces. The stationary blade 56 is fixedly mounted on the frame end plate 22 such that it is aligned with the proximal side 60 of the outlet opening 24. The movable blade 58 is mounted on a support bracket 62. One end of the support bracket 62 is slidably mounted on the end plate 22 within a cutting guide rail 64. The cutting guide rail 64 is positioned beyond a lateral side 66 of the outlet opening 24 and is inclined toward the distal side 67. The support bracket 62 also extends beyond the near/far sides 60/68 of the outlet opening 24.

The other end of the support bracket 62 is pivotally attached to the end plate 22 at a pivot point 70. An intermediate (but not necessarily central) portion of the support bracket 62 is connected to a link 72 which is pivotally connected to a movement block 74 at a pivot point 76. A shaft 78 is connected at one end to the movement block 74 and extends from the downstream side of the frame end plate 22, through the open offset slot 80 to the upstream side of the plate 22. The opposite end of the shaft 78 is operatively connected to

- 11 -

• · &Ggr;

the cutting motor 36 through the solenoid and clutch arrangement 38 (see Figure 1).

The cutting assembly 34 additionally includes a trimming device 82. The trimming device 82 has a trimming member 84 that is connected to the movable blade 58 via a connecting member 86. The trimming device additionally includes a support surface 88 that is aligned parallel to the end plate 22 and that has a recess 90 for accommodating the cutting guide rail 64. The end of the support surface 88 that is closest to the cutting guide rail 64 is pivotally attached to the end plate 22 at a pivot point 92. In the cutting assembly 34, the trimming member 84 is a planar frame that is attached to the support surface 88 and extends perpendicularly downstream from the support surface 88. Furthermore, the connecting part 86 is a connecting part that is attached to one end (exactly the end opposite the pivot point 92) of the support surface 88.

During operation of the cutting assembly 34, the motion block 74 is rotated so that the movable blade 58 moves between a rest position and a cutting position. More specifically, the position of the drive link 72 is changed to move the support bracket 62 (and hence the movable blade 58 and the trim member 84) back and forth within the guide rail 64 at a desired interval. When the motion block 74 is rotated 180° in one direction, the movable blade 58 makes a cutting stroke through the embossed strip 50 as shown in Fig. 3, and when the motion block is rotated another 180°, the movable blade 58 makes a return stroke to the rest position of Fig. 2.
For further details of a damping converter machine, see U.S. Patent No. 5,123,889 or U.S. Patent Application Nos.

- 12 -

08/011,349; 08/066,337; 07/840,306; and 07/592,572.

Both a master control of the feeding and cutting operations of the machine and an indication in the event that the cutting blade is unable to complete the cut of the embossed strip 50 fed by the machine 10 is provided by a control circuit 100 shown in Figs. 4A-4C.

&iacgr;&ogr; In the embodiment of the circuit 100 illustrated in Figures 4A to 4C, two different modes of operation of the device are provided. In the first mode of operation, called the automatic feed mode, a predetermined length of embossed strip 50 is automatically fed through the machine 10 after each cut. The

The embossed strip 50 is cut by the operator pressing a pair of cutting buttons simultaneously. In the second mode of operation, called the foot switch mode, the embossed strip 50 is fed as long as a foot switch is depressed. After the operator releases the foot switch, the embossed strip 50 fed by the machine is automatically cut. The mode of operation of the control circuit 100 is determined by the position of a mode selector switch. These two modes of operation of the machine 10 are described below following a general description of the circuit 100.

Referring specifically to Fig. 4A, the control circuit 100 is powered by a connection between a connector 102 and a power supply (not shown). Power is applied via the power line 104 through safety switches 106, 108 which interrupt power to the feed and cutting motors 30, 36, respectively, if the top or front cover of the machine is not

- 13 -

are closed and via the emergency stop switch 110. The emergency stop switch 110 allows power to be interrupted by pressing a suitable button on a control panel (not shown). A main on/off switch 112, preferably also located on the control panel, is provided to allow overall control of the power to the machine 10. Operation of the machine 10 is generally effected by the feed motor 30 (Fig. 4B), the cutting motor 36 and the cutting solenoid 114 (Fig. 4C).

&iacgr;&ogr; The cutting motor 36 is electrically connected to the power supply line 104 through the solid state relay 116. The relay 116 is controlled by the state of the normally closed encoder contacts TR3a and TR4a, which are controlled by the encoder relays TR3 and TR4 (Fig. 4C), respectively, and the state of the latch contacts LRa

is controlled by latch relay circuit 118. The pulser relay TR3 is set for a relatively long time period and causes the cutting motor 36 to shut down by opening the normally closed contacts TR3a when an embossed strip has not been cut within an extended period of time. The pulser relay TR4 is a miscut pulser which causes the cutting motor 36 to shut down by opening the normally closed pulser contacts TR4a when the time required to make a cut exceeds a predetermined time appropriate for the cutting assembly 34 to accomplish a normal cutting cycle. The latch contacts LRa are closed when normal operation of the machine is initiated and the reset button 120 is pressed, as will be discussed below. Consequently, during normal operation of the machine, the pulse generator contacts TR3a and TR4a and the latch contacts LRa are closed, which continuously supplies voltage to relay 116 via the voltage supply.

supply line 104. This in turn causes relay 116 to supply voltage to cutting motor 36 from voltage supply line 104. Consequently, during normal operation of the machine, without long delays between cutting operations long enough to cause pulser relay TR3 to interrupt, cutting motor 36 will run continuously.

As explained above, the cutting motor 36 is mechanically connected to the cutting assembly 34 by a solenoid and clutch assembly 38

4C, the cutting solenoid 114 of the solenoid and clutch assembly 38 is activated by applying voltage either through a path 122 to the power supply line 104 controlled by the state of the normally open contacts ATDa, or through a path 124 controlled by the states of the normally open encoder contacts TRIa, the normally closed contacts TR2a, the mode selector switch 126, and the foot switch 127 (Fig. 4B). The state of the contacts ATDa is controlled by the tie-down sensor ATD, while the states of the encoder contacts TRIa and TR2a are controlled by the encoders TR1 and TR2, respectively. The pulse generator TR1 determines the length of time that the feed motor 30 will run in the automatic feed mode of operation and thus the length of the embossed strip 50 to be fed by the machine 10. The pulse generator TR2 determines the length of time that the cutting solenoid 114 is activated, approximately one-half second after the appropriate length of embossed strip 50 has been fed by the machine 10 during the foot switch mode of operation. In the automatic feed mode of operation, the embossed strip 50 that is automatically fed by the machine 10 is cut when the operator presses the two cutting buttons 128, 130 simultaneously.

- 15 -

When the cutting buttons 128, 130 are pressed simultaneously, the voltage is switched from the terminal 132 via line 131 to the terminal 134 of the ATD via line 133, causing the normally open contacts to close.

s ATDa is effected. When the contacts ATDa close, voltage is applied from the supply line 104 to the cutting solenoid 114 via path 122, causing the clutch of the solenoid and clutch assembly 38 to engage the cutting motor 36 and rotate the shaft 78 and the motion block 74 to effect a cutting operation of the

Î cutting arrangement 34. Simultaneously with the closing of the contacts ATDa, the contacts ATDb open, thereby resetting the pulse generator relay TRl. If the cutting buttons 128, 130 are not pressed simultaneously or are not pressed within a very short time of each other, the ATD determines that there is no voltage from

is transmitted from terminal 132 to terminal 134 within the specified time, and even though both cutting buttons 128, 130 are depressed, the ATD will not cause the contacts ATDa and ATDb to change state. Therefore, the cutting solenoid 114 will not be activated and the cutting assembly 34 will not move. In this way, the ATD causes the safety feature of providing the two cutting buttons 128, 130 to be able to be overridden by locking one cutting button in the depressed state.

When the machine 10 is in the foot switch mode, after the operator releases pressure from the foot switch 127 (Fig. 4B), when the desired length of embossed strip 50 has been fed through the machine, voltage is applied via the foot switch from the supply line 104 to the line 124. Since the pulser relay TR1 is not reset in the foot switch mode, as described below

discussed in more detail, the contacts TRIa will be in a closed position and voltage is applied from the supply line 104 through the normally closed contacts TRIa and the closed contacts TR2a, via the closed mode selector switch 126, to the cutting solenoid 114, thus energizing the cutting solenoid and causing the solenoid and clutch assembly 138 to engage the cutting motor 36 and the cutting assembly 34 for one complete revolution of the motion block 74. At the same time, the pulser relay TR2 is supplied with voltage via line 138 and &iacgr;&ogr; begins to count down. When the pulser relay TR.2 interrupts once, after approximately half a second, during which the cutting solenoid 114 actuates the clutch of the solenoid clutch assembly 38, the pulser contacts TR2a are opened and the voltage supply to the cutting solenoid 114 via the line 124 is terminated.

As can be seen from Fig. 4B, the feed motor 30 is adjustable in voltage from the power supply line 104 through the solid state relay 140. The relay 140 is in turn controlled by the state of the latch relay contacts LRd in conjunction with the feed pulser contacts TRIb or the feed pulser bypass circuit 142. Since the latch contacts LRb are always closed during normal operation of the machine 10, the state of the feed pulser contacts TRIb or the feed pulser bypass circuit 142 determines whether the feed motor 30 is currently running to feed paper through the machine. In the automatic feed mode, the feed motor 30 is controlled solely by the state of the feed pulser contacts TRIb as determined by the feed pulser relay TRl. (Although an additional embossed strip can be caused to be printed by the machine by using the foot switch 127 in

·

- 17 -

In this way, voltage is applied to relay 140 from line 141 as long as feed pulser contacts TRIb are closed. Thus, embossed strip 50 is fed from machine 10 from the time feed pulser relay TR1 is reset after a cutting operation until pulser relay TR1 breaks, thereby opening contacts TRIb. In foot switch mode, when foot switch 127 is depressed, a bypass circuit 142 is formed which

Î bypasses the feed pulser contacts TRIb. Consequently, current flows over the power supply line 104, through the cutting buttons 128, 130, through lines 131 and 141, through the closed contacts LRb of the latch relay, through the bypass circuit 142 to the relay 140 to drive the feed motor 30 over line 143. Voltage is applied to the relay 140 to energize the feed motor 30 as long as the foot switch 127 is depressed. When power is applied to the feed motor 30 via lines 131 and 141, in both the automatic feed mode and the foot switch mode, the power can be interrupted by either the depressed cutting buttons 128, 130 or a blade switch 144 (Fig. 4C) moving from terminal 146 to terminal 148, which occurs when the cutting assembly 34 begins to move through a cutting cycle, as described in more detail below. Thus, whenever a cutting operation occurs, the power to the feed motor 30 is interrupted, thus preventing jamming of the machine 10.

The operation of the machine 10 in the automatic feed mode will now be discussed in detail. Reference is initially made to Fig. 4A. When the machine 10 is initially powered up, as by closing

of the main power switch 112, current flows through the supply lines 104 to energize the various components of the machine 10, such as the cutting motor 36, the feed motor 30, the cutting solenoid 114, and various encoders. To begin operation in the automatic feed mode, the reset button 120 is depressed and current flows from the supply line 104 through the normally closed encoder contacts TR4a, into line 150 and through line 152 to the latch relay circuit 118. When the latch relay circuit 118 is energized, the

Î contacts LRa of the latch relay in Fig. 4A and LRb in Fig. 4B are closed. Thus, voltage is applied from the power supply line 104 via line 150 through the closed pulser contacts TR4a and TR3a and the closed latch relay LRa to the relay 116, which thus applies voltage from the line 154 to the cutting motor 36

is applied, causing the cutting motor to begin running continuously. Since the latch relay contacts LRb are now closed, current flows from the supply line 104 through the cutting buttons 128 and 130 shown in Fig. 4C, through lines 131 and 141 through the latch relay contacts LRb (Fig. 4B) and the feed pulser contacts TRIb to the relay 140. Consequently, the feed motor 30 is energized by the relay 140 from line 154. The feed motor 30 will continue to run, thereby feeding the embossed strip 50 through the opening 24 and out of the machine 10, as long as the feed pulser relay TR1 has not interrupted. As can be seen in Fig. 4C, the feed pulser TR1 is supplied with voltage from the supply line 104 via the normally closed contacts ATDb from the initial start-up of the machine. The time required for the feed pulser relay TR1 to break thus determines the length of the embossed

strip 50 fed by the machine 10 during the automatic feeding mode of operation.

When the feed pulser relay TR1 breaks, the feed pulser contacts TRIb shown in Fig. 4B open, thereby removing the voltage from relay 140, which in turn interrupts the voltage supply to feed motor 30. When it is desired that the embossed strip 50 fed by machine 10 be cut, the operator simultaneously depresses the cut buttons 128 and 130 (Fig. 4C), thereby transferring voltage from ATD terminal 132 via line 131 to ATD terminal 134 via line 133. Provided that cut buttons 128 and 130 are depressed simultaneously or nearly simultaneously, the ATD relay opens the normally closed contacts ATDb,

is thereby resetting the feed pulser relay TR1 and closes the normally open contacts ATDa, thereby applying voltage to the cutting solenoid 114 from the supply line 104 via line 122. When voltage is applied to the cutting solenoid 114, the cutting solenoid causes the clutch of the solenoid and clutch assembly 138 to couple the cutting motor 36 to the shaft 78, thereby rotating the motion block 74 to drive the cutting assembly 34 through a complete cutting cycle. During the cutting cycle, the support bracket 62 and the movable blade 58 move toward the stationary blade 56 to cut the embossed strip 50 as shown in Fig. 3. When the support bracket 58 moves in this direction, a button 160 of the blade switch mechanism 144, which is normally depressed and holds the blade switch 144 (shown schematically in Fig. 4C) in a position contacting the contact 146, protrudes and loses contact with the support bracket 62, as shown in Fig. 3, thereby causing

- 20 -

that the blade switch 144 in Fig. 4C makes contact with the contact 148 and interrupts the voltage along the line 141.

As soon as the operator releases the cutting buttons 128 and 130, voltage is again applied to the terminal 132 of the ATD relay via line 131. The ATD consequently opens the relay contacts ATDa, which disengage the cutting solenoid 114. At the same time, the ATD relay closes the relay contact ATDb, causing voltage to be applied to the feed pulser relay TRl via line 166, and

‘ the feed pulser relay TR1 begins to count down again. If the feed pulser relay TR1 has not yet interrupted, the feed pulser contacts TRIa in Fig. 4C are open and the feed pulser contacts TRIb in Fig. 4B are closed. As soon as the cutting assembly 34 has completed a cut and the latch switch 144 is in contact with contact 146, voltage is applied from the supply line 104 to the relay 140 via lines 131 and 141 through the latch contacts LRb and the feed pulser contacts TRIb. The relay 140 consequently applies voltage from the line 154 to the feed motor 30 and a predetermined length of the embossed strip 50 is again automatically fed through the machine 10 until the feed pulser relay TR1 interrupts.

The operation of the machine in foot switch mode will now be explained in detail. Again, the machine 10 must be powered up, such as by closing the main power switch 112 and reset by pressing the reset button 120. When the reset button 120 is depressed, current flows from the supply line 104 through lines 150 and 152 to the latch relay circuit 118. The latch relay LRa is closed, allowing current to flow to the relay 116.

to power the cutting motor 36 and the latch relay contacts LRb in Fig. 4B are closed. Since the latch relay contacts LRb are closed and the feed pulser contacts TRIb are also closed when the feed pulser TOl has not yet expired, voltage is initially applied to relay 140 via lines 131 and 141 to cause a first embossed strip to be fed through the machine by the feed motor 30. To begin operation in the foot switch mode, the mode selector switch 126 is closed. If the operator then wishes

‘ As another embossed strip 50 is fed through the machine 10, the operator depresses the foot switch 127. After depressing the foot switch 127, the upper contacts 168 are closed and the lower contacts 170 are opened. By closing the upper contacts 168, the bypass circuit 142 is closed and

is therefore allows power to flow to relay 140 as provided via lines 131 and 141 regardless of the status of the feed pulser contacts TRIb. As long as relay 140 is energized, it will in turn apply voltage applied from line 154 to feed motor 30 via line 143. In this way, feed motor 30 will continue to feed the embossed strip through machine 10 as long as foot switch 127 is depressed. When the operator removes pressure from foot switch 127, upper contacts 168 open, thereby opening bypass circuit 142 and interrupting power to relay 140 and thereby to feed motor 30. At the same time, lower contacts 170 connecting line 124 to supply line 104 are closed. When the feed pulser relay T ¹ has interrupted Rl, the feed pulser contacts TRIa are closed and voltage is applied to the cutting solenoid 114 via the line 124 through the closed feed pulser contacts TRIa, which are normally

- 22 -

the closed pulser contacts TR2a and through the mode selector switch 126. The cutter solenoid 114 is thereby energized, causing the solenoid and clutch assembly 38 to engage the cutter motor 136 and the shaft 78. It is only necessary that the solenoid 114 be energized for a short time, such as one-half second, to cause the solenoid and clutch assembly 38 to couple the cutter assembly 34 to the cutter motor 36 to provide a complete cutting cycle. Consequently, the pulser relay TR2 is energized for an appropriate period of time

&iacgr;&ogr; and since voltage is applied to timing relay TR2 along line 138 at the same time as voltage is initially applied to cutting solenoid 114 via line 124, it will begin to interrupt as soon as the cutting solenoid is energized. After the appropriate interrupt period, timing relay TR2 opens timing contacts TR2a, thereby disengaging cutting solenoid 114. At the same time, normally open timing contacts TR2b are closed, thereby applying voltage along line 172 to timing relay TR3. Timing relay TR3 is a timing relay used to set the time between cuts. When the time between cuts exceeds a predetermined time, e.g. e.g., three to five minutes, the pulser relay TR3 interrupts by opening the pulser contacts TR3a (Fig. 4A) and shuts off the cutting motor 36 to prevent wear on the otherwise continuous cutting motor. After the cutting operation of the cutting assembly 34 has been completed, the blade contact switch 144 returns to the touch contact 146, thereby closing line 141 and allowing the operator to again depress the foot switch 127 to continue feeding an embossed strip 50 through the machine 10.

- 23 -

In both the automatic feed mode and the foot switch mode, cut error detection and indication is provided by a timer relay TR4 which sets the duration necessary for the cutting assembly 34 to complete a complete cutting cycle. Briefly Referring to Figs. 2 and 3, the support bracket 62 is shown contacting and depressing the button 160 of the blade switch mechanism 144 when the cutting assembly 34 is in its rest position (Fig. 2). At this moment, the blade switch 144 is in a position to connect terminal 146 as shown schematically in Fig. 4C.

Ø touches and the pulser TR4 is in a reset mode. When a cutting cycle of the cutting assembly 34 begins, the support bracket 62 and the attached blade 58 move toward and across the opening 24 in the frame end plate 22 through which the embossed strip 50 is fed. When the support bracket 62 moves from its rest position, it no longer touches or depresses the button 162 of the blade switch mechanism 144, as shown in Fig. 3, and the blade switch 144, as illustrated schematically in the circuit diagram of Fig. 4C, moves to a position where it touches the terminal 148. When the blade switch 144 is in this position, current flows through line 141 to line 144 to energize the pulser relay TR4. If the cutting operation of the cutting assembly 34 takes too long to complete, for example if the support bracket 62 and attached blade 58 are unable to cut through the embossed strip 50 as shown in Fig. 3, the contact button 160 remains in its non-depressed position and voltage is continuously provided to the pulser relay TR4 of Fig. 4C. If the cutting operation takes longer than a predetermined time, approximately 3 seconds, the pulser TR4 interrupts, thereby closing the normally open pulser contacts TR4b and continuously providing voltage to the pulser relay TR4.

- 24 -

the line 174 is applied from the supply line 104. The pulse generator relay TR4 is thus brought into an interrupted state and thereby holds the pulse generator contacts TR4a in an open position and the pulse generator contacts TR4c in a closed position (see Fig.

4A) until the machine 10 is reset. When the pulser contacts TR4a are open, the voltage on relay 116 is interrupted, causing relay 116 to shut off power to cutting motor 36. In this way, wear on cutting motor 36 is minimized during a miscut. The pulser contacts TR4c, which are closed when the pulser relay TR4 interrupts, enable power to be supplied to a knife return lamp 176 via line 178 to illuminate the knife return lamp. Consequently, when a miscut fault has occurred, the knife return lamp 176 will illuminate as shown in Fig. 3, thereby providing the operator with a visual indication that a miscut fault has occurred.

The machine 10 also includes a time indicator 180, as shown in Fig. 4B, which is energized via line 182 whenever power is applied to relay 140 to drive feed motor 30. The time indicator 180 records the total amount of time spent feeding the embossed strip 50 from the machine. The machine 10 also preferably includes a push button reversing switch 184 for operating the feed motor 30 in reverse, for example to more easily release the embossed strip 50 that has become jammed in opening 24, for example during a cutting operation. The reversing push button switch 184 is energized directly from line 131. The circuit 100 can be equipped with many other additional functions,

- 25 -

for example, an acoustic cutting error indication signal could be provided.

Although the invention has been shown and described with reference to certain preferred embodiments, it is obvious that equivalent variations and modifications will occur to those skilled in the art after reading and understanding this specification. The present invention includes all such equivalent variations and modifications and is limited only by the scope of the following claims.

Claims (9)

Ranpak Corporation 22 November 1994 R 21022 G/KK/cp 6hm Claims 1. Apparatus for producing a damping pad product, comprising: &iacgr;&ogr; - a frame (12); a conversion assembly mounted on the frame (12) driven by a feed motor (30) for converting stock material fed from a stock material roll into a dampening product (50); a cutting assembly (34) also mounted on the frame (12) which performs a cutting operation to cut the damping product (50) into cut pieces, the cutting assembly (34) having a blade (58) movable between a rest and second position and a cutting motor (36) for driving the blade (58); characterized, that the cutting assembly (34) includes a sensor for detecting when a cutting operation is in progress, a pulse generator that measures the duration of time for a cutting operation to occur, and a circuit (100) that protects the feed motor (30) from operating while the blade (58) is not in the rest position and which interrupts the electricity supply to the cutting motor (36) if the duration exceeds a predetermined period. 2. Device according to the preceding claim, characterized in that the frame (12) has an upstream end (14) and a downstream end (16); the conversion assembly comprises a shaping assembly (26) disposed between the upstream end (14) and the downstream end (16) of the frame (12) and which directs the lateral, outer edges of the web-like material inwards; a supply assembly is arranged at the upstream end (14) of the frame (12) for supplying the stock material from a supply roll to the forming assembly (26); a pulling assembly (28) is arranged downstream of the forming assembly (26) for pulling the feedstock material from the supply assembly through the forming assembly (26); the cutting assembly is disposed at the downstream end (16) of the frame (12), the cutting assembly (34) including a motor (36) for cyclically moving the blade (58) from the rest position to the second position and back to the rest position to complete a cutting operation. 3. Device according to one of the preceding claims, characterized in that the sensor has a contact switch. 4. Device according to claim 2 or 3, characterized in that the feed motor (30) drives the pulling arrangement (28). 5. Device according to one of the preceding claims, characterized in that the pulse generator is reset each time the blade (58) returns to its rest position. 6. Device according to one of the preceding claims, characterized by a forcing arrangement (40) which is arranged downstream of the &iacgr;&ogr; cutting arrangement (34) is arranged to cut the damping product to generally force during a cutting operation. 7. Device according to one of claims 2 to 6, characterized in that the shaping arrangement (26) and the drawing arrangement (28) cooperate to form the damping product (50). 8. Device according to one of the preceding claims, characterized by a gear arrangement which forms an embossed strip along a central band of the damping product. 9. Device according to one of claims 2 to 8, characterized in that the forming arrangement (26) comprises a slideway (46) through which the stock material is drawn and that the lateral edges of the stock material are rolled inwardly into a generally spiral-like shape.