GB2284073A - Fault indication in a cutting machine - Google Patents

Abstract

A cutting machine includes a miscut detection circuit which employs a timer to determine the length of time that the machine is cutting and interrupts power to the actuator of the blade when the time exceeds a predetermined value. The cutting machine is included in a corrugated paper making machine.

Description

A CUSHIONING CONVERSION APPARATUS In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional commonly used protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to adequately perform as cushioning products, they are not without disadvantages. For example, one drawback of plastic bubble film is that is usually includes a polyvinylidene chloride coating. This coating prevents the plastic film from being safely incinerated, which often creates disposal difficulties.Additionally, both the plastic foam peanuts and the plastic bubble pack have a tendency to generate a charge of static electricity attracting dust from the surrounding packaging site. Also, these plastic materials sometimes themselves produce a significant amount of packaging "lint". Such dust and lint particles are generally undesirable and may even be destructive to sensitive merchandise such as electronic or medical equipment.

Perhaps the most serious drawback of plastic bubble wrap and/or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet's already critical waste disposal problems. The non-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 conventional plastic packaging materials have made paper protective packaging material a very popular alternative. Paper is biodegradable, recy able and renewable; making it an environmentally responsible choice for conscientious indt:stries. Additionally, paper may be safely inclnerated by the recipients of the products.

Furthermore. paper protective packaging material is perfect for particle-sensitive mercnandise, as its clean dust-free surface is resistant to static cling.

While paper in sheet form could possibly be used as a protective packaging material, it is usually preferably to convert the sheets of paper into a relatively low density pad-like cushioning dunnage product. This conversion may be accomplished by a cushioning conversion machine, such as that disclosed in U.S. Application Nos. 08/066,337; 07/S40.306; 07/712,203 (now Patent No. 5,123,889); and 07/592,572.

Such a cushioning conversion machine converts sheet-like stock material, such as paper in multi-ply form, into cut sections of a relatively low density pad-like cushioning product. The stock material may consist of thre superimposeå webs or layers of biodegradable. recyclable and reusable thirty-pound Kraut paper rolled into a hollow cylindrical tube. A thirv-inch roll of this paper, which is approxuTnatels 450 feet long, will weight about 35 pounds and will provide cushioning equal to approximately four fifteen cubic foot bags of plastic foam peanuts while at the same time requiring less than one-thirtieth the storage space.

Specifically, the machine converts the stock material into a continuous unconnected strip having lateral pillow-like portions separated by a thin central band. This strip is connected or coined along the central band to form a coined strip which is cut into sections of a desired length. The cut sections each include lateral pillow-like portions separated by a thin central band and provide an excellent relatively low density pad-like product which may be used instead of conventional plastic protective packaging material.

The cushioning conversion machine disclosed in the above-identified applications includes a frame having an upstream end and a downstream end. (The terms "upstream" and "downstream" in this context are characteristic of 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 small rectangular outlet 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 post cutting constraining assembly, all of which are mounted on the machine frame. In operation of the machine, the stock supply assembly supplies the stock material to the forming assembly. The forming assembly causes inward rolling of the lateral edges of the sheet-like stock material to form the lateral pillow-like portions of the continuous strip. The gear assembly pulls the stock material through the machine and also coins the central band of the continuous strip to form the coined strip. The coined strip travels downstream from the gear assembly and through the outlet opening in the end plate. The cutting assembly, which is mounted on the downstream side of the end plate, cuts the coined strip into sections of a desired length.These cut sections then travel through the post-cutting constraining assembly.

The post-cutting constraining assembly is located downstream of the cutting assembly and .s mounted on the box-like extension. The pos:-cutring constraining assembly is baslcily tunnel-shaped and is positioned so that irs inlet is aligned with the outlet opening of the end plate. A cut section will be urged or pushed downstream through the posteutting constraining assembly by the approaching coined strip. As the cut section passes through the postNuttins constraining assembly, it is constrained circumferentially to improve its cushioning quality.

In the above-identified applications, the cutting assembly includes a stationary blade and a moving blade, both of which are strategically positioned relative to the outlet opening.

During operation of the cutting assembly, the moving blade travels between a rest position and a cutting position. More specifically, the moving blade will travel through one cycle of making a cutting stroke and a return stroke to the rest position. During the cutting stroke, the moving blade travels across the outlet opening and coacts with the stationary blade. For example. the moving blade can coact with the stationary blade in a "guillotine-like" fashion or, alternatively, coact with the stationary blade in a "scissor-like" fashion.

Applicants believe that the cutting assemblies disclosed in the above-identified applications adequately perform their cutting functions. Nonetheless, applicants also appreciate that, in certain situations, the cutting assembly can fail adequately to cut the coined strip because of the coined strip becoming jammed between the moving blade and the stationary blade, for instance. It would be desirable to provide a cutting apparatus and circuit which provided fault indication to indicate to an operator that the cutting assembly has failed to cut the coined strip and to provide a cutting assembly and circuit which prevents excessive wear to the machine during a miscut.

According to the invention, there is provided a cushioning conversion apparatus comprising: a frame; a conversion assembly mounted on said frame for converting stock material, fed by a feed motor, into a cushioning product; and a cutting assembly mounted on said frame for performing a cutting operation to cut cushioning product into cut sections, said cutting assembly including a blade moveable between a rest position and a second position, a motor for powering said blade, a sensor for sensing when a cutting operation is in progress, a timer for measuring the time from the initiation of a cutting operation until said sensor detects that the cutting operation has ceased, and a circuit for preventing said feed motor from operating while said blade is not in said rest position and which interrupts electrical power to said motor if said measured time exceeds a predetermined amount.

This invention generally relates to a cushioning conversion apparatus including a cutting assembly. Thus, there is provided a cushioning conversion apparatus including a cutting assembly which includes miscut detection circuit . Particularly, this invention relates to a miscut detection circuit which detects when a cutting apparatus has failed to complete a cutting process within a prescribed period of time. More particularly, the miscut detector circuit may optionally be employed in a cushioning conversion machine and may act to turn on an indicator light to provide a visual fault indication when a miscut has occurred and interrupts electrical power to a motor powering the cutting apparatus to protect the motor and other components of the machine when a miscut has occurred.

?'iie p.es-.t invene ^n provides 2 cutting apparatus with a miscut detection circuit which employs a timer to determine the length of time that the machine is undergoing a cutting operation. When the time exceeds a predetermined duration suitable for a proper cutting operation, a fault indicator lamp mav be lit and/or the cutting operation is discontinued.

In accordance with one aspect of the present invention, a cutting apparatus includes a blade movable between first and second positions, the blade coacting with another surface for cutting a material, a motor for moving the blade between the first and the second positions, a sensor for detecting when the blade is in the first position, a timer for timing the duration the blade is not in the first position; and a relay for interrupting power to said motor when the duration the blade is not in the first position exceeds a predetermined duration. The cutting apparatus may also include a relay operative to light a fault indicator lamp when a miscut has occurred.

In accordance with another aspect of the invention a miscut detection circuit includes a power supply means for providing electrical power to a motor to cause a blade to move between a first position and a second position. a detector for detecting when the blade is away from the first position, a timer for timing 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 circuit preferably lights a fault indicator lamp when a miscut has occurred.

There now follows a description of a preferred embodiment of the invention, by way of example, with reference being made to the accompanying drawings in which: Figure 1 is a top view of an exemplary cushioning conversion machine into which the apparatus and functions of the present invention may be employed; Figure 2 is an elevation view of the cutting assembly of the cushioning conversion machine of Figure 1; Figure 3 is an elevation view of the cutting assembly of Figure 2 shown in a partially cut position; and Figures 4A through 4C are electrical schematic diagrams of a miscut detection circuit according to the present invention.

Referring now to the drawings in detail and initially to Figures 1 through 3, there is shown an exemplary machine 10 in which the present invention may be employed. The mplary machine 10 depicted in Figures 1 through 3 is a cushioning conversion machine which converts a number of lavers of recyclable and reusable Kraft paper into a continuous unconnected strip having lateral pillow-iSe portions separated by a thin central band. This material is used as an environmentally responsible protective packaging material typically used during shipping.

The machine 10 includes a frame, indicated generally at 12, having an upstream end 14 and a downstream end 16. The Kraft paper from which the packaging material is made is unwound from a roll (not shown) near the upstream end 14 of the frame 12, passes through the machine 10, and emerges at the downstream end 16. The frame 12 is formed from a b::se 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 cushion to emerge from the frame 12. The machine 20 further includes a stock supply assembly (not shown), a forming assembly 26. a feed gear assembly 28 powered bv a feed motor 30 through a motion transfer assembly 32, a cutting assembly 34 powered by a cut motor 36 through a solenoid and clutch arrangement 38; all of which are mounted on the frame 12. A post-cutting constraining assembly 40 is located downstream of the cutting assembly 34 and is mounted on a removable box-like extension 42 at the downstream side 16 of the frame 12.

In operation of the machine 10, stock supply material is supplied to the forming assembly 26 where it enters the shaping member 44 and converging chute 46. The forming assembly 26 causes an inward rolling of the lateral edges of the sheet-like stock material to form lateral pillow-like portions of the continuous strip stock material. The feed gear assembly 28 performs dual functions in the operation of the machine 10. One function is a "feeding" function in which the material is drawn through the nip of two cooperating and opposed gears of the gear assembly 28. Thus the feed gear assembly 28 is the mechanism which pulls the stock material from a stock roll, through the shaping member 44 and converging chute 46 of the forming assembly 26, over the guide tray 48 and through the rectangular opening 24 in the end plate 22.The second function performed by the feed gear assembly 28 is a "coining" or "connecting" function. Specifically, the feed gear assembly 28 connects the continuous strip by two opposing gears coining its central band passing therethrough to form the coined strip 50, shown in Figures 2 and 3. As the coined strip 50 travels downstream from the feed gear assembly 28 through the opening 24 it passes through the cutting assembly 34 which cuts the strip into sections of a desired length. These cut sections 50 then travel through the post-cutting constraining assembly 40, which includes a converging portion 52 and rectangular tunnel portion 54. The coined strip 50 then emerges from the rectangular tunnel portion 54 where an operator may remove the coined strip from the machine 10.

The cutting assembly 34 is better shown in Figures 2 and 3. The cutting assembly 34 includes a stationary blade 56 and a moving blade 58, both of which are strategically positioned relative to the outlet opening 24. The blades 56 and 58 are the actual "cutting' elements of the cutting assembly 34 and coact in a scissor-like fashion to cut the coined strip 50 into cut sections. The stationary blade 56 is fixedly mounted on the frame end plate 22 in such a manner that it is aligned with the proximal side 60 of the outlet opening 24. The moving blade 58 is mounted on a support bar 62. One end of the support bar 62 is slidably mounted on the end plate 22 within a cutter guide track 64.The cutter guide track 64 is positioned beyond one lateral side 66 of the outlet opening 24 and slants toward its distal side 67. The support bar 62 also extends beyond the proximal/distal sides 60/68 of the outlet opening 24.

The other end of the support bar 62 is pivotallv attached to the end plate 22 at a pivot point 70. An intermediate (but not necessarily central) part of the suppon bar 62 is connected to a drive link 72 which is pivotally connected to a motion block 74 at the pivot point 6. A shaft 78 is connected at one end to the motion 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 operably connected to the cutter motor 36 through the solenoid and clutch aaaangernent 38 (see Figure 1).

The cutting assembly 34 additionally includes an alignment device 82. The alignment device 82 includes an alignment member 84 which is interconnected with the moving blade 58 via a connecting member 86. The alignment device 82 additionally includes a support panel 88 which is orientated parallel to the end plate 22 and which includes a notch 90 for accommodating the cutter guide track 64. The end of the support panel 88 closest to the cutter guide track 64 is pivotally attached to the end plate 22 at a pivot point 92. In the cutter assembly 34, the alignment member 84 is a planar shelf which is attached to, and extends perpendicularly downstream from, the support panel 88. Additionally, the connecting member 86 is a link member which is attached to an end (specifically, the end opposite the pivot point 92) of the support panel 88.

During operation of the cutting assembly 34, the motion block 74 is rotated so that the moving blade 58 travels between a rest position and a cutting position. More specifically, the position of the drive link 72 is varied to move the support bar 62 (and thus the moving blade 58 and the alignment member 84) to and fro within the guide track 64 at a desired interval. As the motion block 74 is rotated 180 in one direction, the moving blade 58 makes a cutting stroke through the coined strip 50, as is shown in Figure 3, and, as the motion block 74 is rotated an additional 180-, the moving blade 58 makes a return stroke to the rest position of Figure 2.

For further details of a cushioning conversion machine reference may be had to U.S.

Patent No. 5,123.889 or to U.S. Patent Application Nos. 08/011,349; 08/066,337; 07/840,306; and 07/592,572.

Principal control of the feed and cut operations of the machine as well as fault indication in the event that the cutting blade is unable to complete the cut of the coined strip 50 fed through the machine 10 is provided by a control circuit 100, shown in Figures 4A through 4C.

in the embodiment of the circuit 100 depicted in Figures 4A through 4C, two different modes of operation of the device are provided. In the first mode of operation, called the automatic feed mode, a preset length of coined strip 50 is automatically fed through the machine 10 after each cut. The coined strip 50 is cut by the operator simultaneously depressing a pair of cut buttons. in the second mode of operation, called the foot switch mode, the coined strip 50 is fed through the device for as long as a foot switch is depressed. Upon the operator releasing the foot switch. the coined strip 50 fed through 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 discussed below following a general description of the circuit 100.

With specific reference to Figure 4A, the control circuit 100 is provided with power through a connection between a plug 102 and a power supply (not shown). Power is supplied across the power supply line 104 through the safety switches 106, 108, which cut off power to the feed and cut motors 30, 36, respectively, when the top or front covers of the machine are not closed. and the emergency stop switch 110. The emergency stop switch 110 ;'ermits power to be interrupted such as by pulling an appropriate button on a control panel (not shown). A master on/off switch 112. also preferably located on the control panel, is provided to allow overall control of power to the machine 10.Operation of the machine 10 is generally effected through the feed motor 30 (Figure 4B), the cut motor 36 and the cut solenoid 114 (Figure 4C).

The cut 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 normally closed timer contacts TR3a and TR4a, which are controlled by timer relays TR3 and TR4 (Figure 4C), respectively, and the state of latch contacts LRa, controlled by the latch relay circuit 118.

Timer relay TR3 is set to a relatively long time out period and acts to turn off the cut motor 36, by opening the normally closed contacts TR3a, when a coined strip has not been cut for an extended period of time. Timer relay TR4 is a miscut timer which acts to shut off the cut motor 36, by opening normally closed timer contacts TR4a, when the time required to make a cut exceeds a preset time adequate for the cutting assembly 34 to perform a normal cut cycle. The latch contacts LRa are closed once normal operation of the machine is begun and the reset button 120 is depressed, as will be discussed below. Consequently, during normal operation of the machine, timer contacts TR3a and TR4a and latch contacts LRa are closed thus causing power to be continuously supplied to the relay 116 from the power supply line 104. This in turn causes the relay 116 to supply power from the power supply line 104 to the cut motor 36. Consequently, during normal operation of the machine, without long delays between cutting operations sufficient to cause timer relay TR3 to time out, the cut motor 36 runs continuously.

As is discussed above, the cut motor 36 is mechanically coupled to the cutting assembly 34 through a solenoid and clutch arrangement 38. Referring generally to Figure 4C, the cut solenoid 114 of the solenoid and clutch arrangement 38 is activated by supplying it with power either through a path 122 to the power supply line 104 controlled by the state of normally open contacts ATDa or through a path 124 controlled by the states of normally open timer contacts TRla, normally closed contacts TR2a, the mode selector switch 126 and the foot switch 127 (Figure 4B). The state of contacts ATDa are controlled by the automatic tie down sensor ATD, while the states of timer contacts TRla and TR2a are controlled by the timers TR1 and TR2 respectively.Timer TR1 determines the length of time which the feed motor 30 will run, and thus the length of coined strip 50 to be fed from the machine 10, in the automatic feed mode of operation. Timer TR2 determines the length of time for which the cut solenoid 114 is activated, about one-half second, after the appropriate length of coined strip 50 has been fed through the machine 10 during the foot switch mode of operation. In the automatic feed mode of operation, coined strip 50 automatically fed through the machine 10 is cut when the operator depresses the two cut buttons 128, 130 simultaneously. When the cut buttons 128, '30 are simultaneously depressed, the power is switched from terminal 132 over line 131 to the terminal 134 of the ATD over line 133 thereby usinf the normally open contacts ATDa to close.When the contacts ATDa close, power 5 supplied from the power supply line 104 to the cut solenoid 114 over path 122, thereby causing the clutch of the solenoid and clutch arrangement 38 to engage the cut motor 36 and rotate the shaft 78 and motion block 74 to effect a cutting operation of the cutting assembly 34. Concurrent with the contacts ATDa closing, contacts ATDb open, thus resetting feed timer relay TR1. If the cut buttons 128, 130 are not simultaneously depressed, or are not depressed within a very short time of each other, the ATD detects that power has not transferred from terminal 132 to the terminal 134 within the specified time, and even though both cut buttons 128, 130 are depressed, the ATD will not cause the contacts ATDa and ATDb to change states.Therefore, the cut solenoid 114 will not be activated and the cutting assembly 34 will not move. In this way, the ATD functions to prevent the safety feature of providing two cut buttons 128, 130 from being circumvented by tying down one cut button in the depressed condition.

When the machine 10 is in the foot switch mode, upon the operator removing pressure from the foot switch 127 (Figure 4B) when the desired length of coined strip 50 has been fed through the machine, power is supplied across the foot switch from the power supply line 104 to the line 124. Since the timer relay TRI is not reset in the foot switch mode, as is discussed more fully below, the contacts TRla will be in a closed position and power will be supplied from the power supply line 104 through the normally closed contacts TRla and the closed contacts TR2a, across the closed mode selector switch 126, to the cut solenoid 114 thus activating the cut solenoid and causing the solenoid and clutch arrangement 138 to engage the cut motor 36 and cutting assembly 34 for one complete revolution of the motion block 74.Simultaneously, the timer relay TR2 is supplied with power over line 138 and begins timing down. Once the timer relay TR2 times out, after approximately one-half second during which the cut solenoid 114 engages the clutch of the solenoid clutch arrangement 38, the timer contacts TR2a are opened and the power supply to the cut solenoid 114 over the line 124 is terminated.

As seen in Figure 4B, the feed motor 30 is controllably supplied power from the power supply line 104 by the solid state relay 140. The relay 140 is in turn controlled by the state of the latch relay contacts LRb in conjunction with the feed timer contacts TRlb or the feed timer bypass circuit 142. As the latch contacts LRb are always closed during normal operation of the machine 10, whether the feed motor 30 is running to feed paper through the machine will be determined by the state of the feed timer contacts TRlb or the feed timer bypass circuit 142.In the automatic feed mode, the feed motor 30 is controlled exciusively by the state of the feed timer contacts TRlb as determined by the feed timer relay TR1. (Although additional coined strip can be caused to be fed through the machine by use of the foot switch 127 in connection with the automatic feed mode.) In this manner, power is supplied to the relay 140 from line 141 as long as feed timer contacts TRlb are closed. Thus coined strip 50 is fed from the machine 10 from the time that the feed timer relay TR1 is reset after a cutting operation until the timer relay TR1 times out, thus opening the contacts TRlb. In the foot switch mode, when the foot switch 127 is depressed, a bypass circuit 142 is formed circumventing the feed timer contacts TRlb.Consequently, power flows from the power supply line 104 across the cut buttons 128, 130 over lines 131 and 141 through the closed latch relay contacts LRb, through the bypass circuit 142 to the relay 140 to power the feed motor 30 over the line 143. Power is supplied to the relay 140 to energize the feed motor 30 as long as the foot switch 127 is depressed. As power is supplied to the feed motor 30 across lines 131 and 141 in both the automatic feed mode and in the foot switch mode, power may be interrupted by either the cut buttons 128, 130 being depressed or a blade switch 144 (Figure 4C) moving from terminal 146 to terminal 148, which occurs when the cutting assembly 34 begins moving through a cutting cycle, as is described more fully below.Consequently, whenever a cutting operation occurs, power is interrupted to the feed motor 30 so as to prevent jamming of the machine 10.

Operation of the machine 10 in the automatic feed mode is now discussed in detail.

With initial reference to Figure 4A, when the machine 10 is originally powered up, such as by closing the master on/off switch 112, power flows through the power supply line 104 to supply power to the various components of the machine 10, such as the cut motor 36, the feed motor 30, the cut solenoid 114 and the various timers. In order to begin operation in the automatic feed mode, the reset button 120 is depressed and power flows from the power supply line 104 through the normally closed timer contacts TR4a in the line 150 and across line 152 to the latch relay circuit 118. When the latch relay circuit 118 is provided power, latch relay contacts LRa in Figure 4A and LRb in Figure 4B are closed.Thus, power is supplied from the power supply line 104 across line 150 through the closed timer contacts TR4a and TR3a and closed latch relay LRa to the relay 116 which thus supplies power to the cut motor 36 from the line 154, causing the cut motor to begin running continuously. As the latch relay contacts LRb are now closed, power flows from the power supply line 104 through the cut buttons 128 and 130, shown in Figure 4C, across lines 131 and 141 through the latch relay contacts LRb (Figure 4B) and the feed timer contacts TRlb to the relay 140.

Consequently, the feed motor 30 is provided power through the relay 140 from the line 154.

The feed motor 30 will continue to run, thus feeding coined strip 50 through the opening 24 and out of the machine 10, as long as feed timer relay TR1 has not timed out. As seen in Figure 4C, feed timer TRf is supplied with power from the power supply line 104 across normally closed contacts ATDb from initial start up of the machine. The duration of time that it takes for feed timer relay TR1 to time out thus determines the length of coined strip 50 which is fed through the machine 10 during the automatic feed mode of operation.

Once feed timer relay TR1 times out, feed timer contacts TRlb shown in Figure 4B open thus discontinuing power to the relay 140 which thus terminates power to the feed motor 30. When it is desired that the coined strip 50 fed through the machine 10 is to be cut, an operator simultaneously depresses cut buttons 128 and 130 (Figure 4C), thus transferring power from ATD terminal 132 over line 131 to ATD terminal 134 over line 133. Provided that the cut buttons 128 and 130 are depressed simultaneously, or sufficiently close to simultaneously, the ATD relay opens normally closed contacts ATDb, thereby resetting feed timer relay TR1, and closes normally open contacts ATDa, thereby supplying power to the cut solenoid 114 from the power supply line 104 over the line 122.When power is supplied to the cut solenoid 114, the cut solenoid causes the clutch of the solenoid and clutch arrangement 138 to engage cut motor 36 with the shaft 78, thereby turning the motion block 74 to drive the cut assembly 34 through a complete cutting cycle. During the cutting cycle. the support bar 62 and moving blade 58 move toward the stationary blade 56 to cut the coined strip 50, as is shown in Figure 3. As the support bar 58 moves in this direction, a button 160 of the blade switch mechanism 144, which is normally depressed and maintains the blade switch 144 (Shown schematically in Figure 4C) in a position contacting contact 146, extends and loses contact with the support bar 62, as shown in Figure 3, thus causing the blade switch 144 in Figure 4C to make contact with contact 148 and interrupt power along line 141.

Once the operator releases cut buttons 128 and 130, power is resupplied to the terminal 132 of the ATD relay over line 131. The ATD thus opens relay contacts ATDa which disengages the cut solenoid 114. Simultaneously, the ATD relay closes relay contact ATDb thus causing power to be supplied to the feed timer relay TR1 over line 166 and the feed timer relay TR1 again begins counting down. As the feed timer relay TR1 has not yet timed out, feed timer contacts TRla in Figure 4C are open and feed timer contacts TRlb in Figure 4B are closed. Once the cutting assembly 34 has completed a cut and blade switch 144 is in contact with contact 146, power is supplied from power supply line 104 to the relay 140 over lines 131 and 141 through latch contacts LRb and feed timer contacts TRlb.The relay 140 thus supplies power from the line 154 to the feed motor 30 and a predetermined length of coined strip 50 is again automatically fed through the machine 10 until the feed timer relay TR1 times out.

Operation of the machine 10 in the foot switch mode is now discussed in detail.

Again, the machine 10 must be powered up, such as by closing the master.on/off switch 112 and reset by pushing the reset button 120. When the reset button 120 is depressed, power flows from the power supply line 104 through lines 150 and 152 to the latch relay circuit 118. Latch relay LRa is closed thereby permitting power to flow to the relay 116 to energize the cut motor 36 and latch relay contacts LRb in Figure 4B are closed. Initially, since latch relay contacts LRb are closed and feed timer contacts TRlb are also closed, as the feed timer TR1 has not yet expired, power is supplied to the relay 140 over lines 131 and 141 to cause an initial coined 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.When the operator then wishes to cause further coined strip 50 to be fed through the machine 10, the operator depresses the foot switch 127. Upon the foot switch 127 being depressed, upper contacts 168 are closed and lower contacts 170 are opened. By closing upper contacts 168, the bypass circuit 142 is closed, therefore permitting power to flow to the relay 140 as provided over lines 131 and 141 regardless of the state of feed timer contacts TRlb. For as long as the relay 140 is provided power, it will in turn provide power supplied from line 154 to the feed motor 30 over line 143. Thus, the feed motor 30 will continue to feed coined strip 50 through the machine 10 as long as the foot switch 127 is depressed.Upon the operator removing pressure from the foot switch 127, upper contacts 168 open therefore opening the bypass circuit 142 and interrupting power to the relay 140 and thereby the feed motor 30. Simultaneously, lower contacts 170 are closed connecting line 124 to power supply line 104. As the feed timer relay TR1 has timed out feed timer contacts TRla will be closed and power will be supplied to the cut solenoid 114 over line 124 through the closed feed timer contacts TRla, the normally closed timer contacts TR2a and across mode selector switch 126. The cut solenoid 114 is thereby energized causing the solenoid and clutch arrangement 38 to bring the cut motor 136 and shaft 78 into engagement.It is only necessarv that the solenoid 114 be energized a short time, for example 1/2 second, in order to cause the solenoid and clutch arrangement 38 to engage the cutting assembly 34 with the cut motor 36 to provide a complete cut cycle. Consequently, timer relay TR2 is provided with an appropriate time duration and, since time relay TR2 is supplied power along line 138 at the same time that power is initially supplied to the cut solenoid 114 over line 124, it will begin to time out as soon as the cut solenoid is energized. After the appropriate time out period, timer relay TR2 will open timer contacts TR2a thereby disengaging the cut solenoid 114. Simultaneously, normally open timer contacts TR2b are closed thereby supplying power along line 172 to timer TR3. Timer TR3 is a timer which acts to time the duration between cuts.If the time between cuts exceeds a predetermined duration, for example three to five minutes, timer relay TR3 will time out thus opening timer contacts TR3a (Figure 4A) and turning off the cut motor 36 to prevent wear on the otherwise continuously running cut motor. After the cutting operation of the cutting assembly 34 has been completed, blade contact switch 144 will return to contacting contact 146 thereby closing line 141 and permitting the operator to again depress the foot switch 127 to have more coined strip 50 fed through the machine 10.

In either the automatic feed mode or the foot switch mode, miscut detection and indication is provided through a timer relay TR4 which times the length that it takes for a complete cut cycle of the cutting assembly 34 to be completed. Referring briefly to Figures 2 and 3, the support bar 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 (Figure 2). In this instance, the blade switch 144, as schematically shown in Figure 4C, is in a position contacting terminal 146 and the timer TR4 is in a reset mode. When a cutting cycle of the cutting assembly 34 begins, the support bar 62 and attached blade 58 move towards and across the opening 24 in the frame end plate 22 through which the coined strip 50 is fed.As the support bar 62 moves away from its rest position, it no longer contacts or depresses button 162 of the blade switch mechanism 144, as is shown in Figure 3, and the blade switch 144, as schematically illustrated in the circuit diagram of Figure 4C, moves to a position to contact terminal 148. When the blade switch 144 is in this position, power flows through line 141 to line 174 to power the timer relay TR4. If the cutting operation of the cutting assembly 34 requires too long to complete, such as when the support bar 62 and attached blade 58 are not able to cut through the coined strip 50, as is shown in Figure 3, the contact button 160 will remain in its non-depressed position and power will be continually provided to the timer relay TR4 of Figure 4C.If the cutting operation takes longer than a predetermined time, approximately 3 seconds, the timer TR4 will time out thereby closing normally opened timer contacts TR4b and causing power to be continually supplied to the timer relay TR4 over line 174 from the power supply line 104. As such, the timer relay TR4 is latched into a timed out condition and will thereby maintains timer contacts TR4a in a open position and timer contacts TR4c in a closed position (see Figure 4A) until the machine 10 is reset. When the timer contacts TR4a are open, power to the relay 116 is interrupted thereby causing the relay 116 to shut off power to the cut motor 36. In this manner, wear and tear on the cut motor 36 during a miscut is minimized.Timer contacts TR4c, which are closed when the timer relay TR4 times out, permit power to be supplied to a knife return lamp 176 over line 178 to light the knife return lamp. Consequently, when there has been a miscut fault. the knife return lamp 276 will light, as is shown in Figure 3, providing a visual indication to an operator that a miscut fault has occurred.

The machine 10 also includes an hour meter 180, such as shown in Figure 4B which is provided power over line 182 whenever power is supplied to the relay 140 to drive the feed motor 30. The hour meter 180 keeps track of the total amount of time that has been expended feeding coined strip 50 from the machine. The machine 10 also preferably includes a reverse push button switch 184 for reversing the feed motor 30 such as to help to clear coined strip 50 which has been jammed in the opening 24, such as during a cutting operation. The reverse push button 184 is provided with power directly from line 131.

Many other ancillary functions could be provided to the circuit 100, for example, an audible miscut indication signal could be provided.

Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications.

.e attention of the reader is directed to pending U.S. Application No.

O8/ll:S.-9, U.S. ApplicatIon No. 5?l2,889 and pending U.S.

08/118,349 U.S. Application No. 08/066,337 Patant No. 5,123,889 and pending U.S.

Application No. 07 592,572 The entire -ooosures of these documents are incorporated herein by this reference.

Claims (9)

1. A cushioning conversion apparatus comprising: a frame; a conversion assembly mounted on said frame for converting stock material, fed by a feed motor, into a cushioning product; and a cutting assembly mounted on said frame for performing a cutting operation to cut cushioning product into cut sections, said cutting assembly including a blade moveable between a rest position and a second position, a motor for powering said blade, a sensor for sensing when a cutting operation is in progress, a timer for measuring the time from the initiation of a cutting operation until said sensor detects that the cutting operation has ceased, and a circuit for preventing said feed motor from operating while said blade is not in said rest position and which interrupts electrical power to said motor if said measured time exceeds a predetermined amount.

2. A cushioning conversion machine according to claim 1 for converting sheet-like stock material into cut sections of relatively low-density pad-like cushioning product, wherein: (i) the frame has an upstream end and a downstream end; (ii) the conversion assembly includes a forming assembly located intermediate said upstream end and said downstream end of said frame and which directs the lateral outside edges of the sheet-like stock material inwardly; (iii) the apparatus Includes: (a) a supply assembly located at the upstream end of said frame for supplying the stock material from a roll of stock to said forming assembly; and (b) a pulling assembly located downstream of said forming assembly including the feed motor for pulling the stock material from said supply assembly through said forming assembly; and (iv) the cutting assembly is located at said downstream end of said frame and the motor for powering the blade cycles said blade from said rest position to a second position and back to the rest position to complete a cutting operation.

3. The cushioning conversion machine of claim 1 or claim 2, wherein said sensor includes a contact switch.

t. The cushioning conversion machine of any of claims 1 to 3, wherein said timer is reset each time that said blade returns to said rest position.

5. The cushioning conversion machine of any preceding claim, further including a constraining assembly located downstream of said cutting assembly to generally constrain the cushioning product during a cutting operation.

6. The cushioning conversion machine of claim 2 or any of claims 3 to 5, (when dependent from claim 2), wherein said forming assembly and said pulling assembly coact to form the cushioning product.

7. The cushioning conversion cf any preceding claim, including a gear assembly which forms a coined strip along a central band of the cushioning product.

8. The cushioning conversion machine of claim 2 or any of claims 3 to 7 (when dependent from claim 2), wherein said forming assembly includes a chute through which the stock material is pulled and wherein the lateral edges of the stock material are rolled inwardly into a generally spiral-like form.

9. A cushioning conversion machine generally as herein described, with reference to or as illustrated in the accompanying drawings.