WO2000027620A1

WO2000027620A1 - Cushioning conversion machine and method

Info

Publication number: WO2000027620A1
Application number: PCT/US1999/026658
Authority: WO
Inventors: Richard O. Ratzel; Donald J. Barnhouse
Original assignee: Ranpak Corp.
Priority date: 1998-11-12
Filing date: 1999-11-10
Publication date: 2000-05-18
Also published as: AU1718500A

Abstract

A cushioning conversion machine (10) including a conversion assembly (12) which converts sheet-like stock material into a strip of dunnage (170) and a severing assembly (16) which severs the strip of dunnage into cushioning pads. The severing assembly (16) includes a blade (106) which moves from a first position to a second position to sever a first section of the strip of dunnage into a first cushioning pad and which moves from the second position back to the first position to sever a second section of the strip of dunnage into a second cushioning pad. A drive assembly (18) may be provided to move the blade (106) between the first and second positions.

Description

CUSHIONING CONVERSION MACHINE AND METHOD

FIELD OF THE INVENTION This invention relates generally as indicated to a cushioning conversion machine and a cushioning conversion method. More particularly, the invention relates to a cushioning conversion machine/method wherein the severing assembly/step allows for an increased production rate of cushioning pads.

BACKGROUND OF THE INVENTION 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. 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 has made paper protective packaging material a very popular alterative. Paper is biodegradable, recyclable and renewable; making it an environmentally responsible choice for conscientious industries. While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the paper into a plurality of relatively low density cushioning pads. This conversion may be accomplished by a cushioning conversion machine, such as those disclosed in U.S.

Patent Nos. 4,619,635; 4,699,609; 5,123,889; and 5,674,172 and U.S. Patent Application Nos.

08/986,525; 60/069,393; (filed December 8, 1997 and December 12, 1997, respectively, and both entitled CUSHIONING CONVERSION MACHINE WITH SINGLE FEED/CUT MOTOR) and 08/676,681 (filed July 10, 1996 and entitled CUSHIONING CONVERSION MACHINE WITH SEVERING MECHANISM). These patents and applications are assigned to the assignee of the present invention and their entire disclosures are hereby incorporated by reference. Each of these cushioning conversion machines includes a conversion assembly which converts a sheet-like stock material into a strip of dunnage and a severing assembly which severs the strip of dunnage into cushioning pads of desired lengths. The conversion assembly typically includes a forming assembly which forms the stock material and a feeding assembly which feeds the stock material through the forming assembly. More particularly, the forming assembly forms the stock material into a strip having lateral pillow-like portions and a central portion therebetween. The feeding assembly connects and/or compresses the central portion to join together overlapped lateral edges of the stock material. In this manner, the converted strip of dunnage has lateral pillow-like portions separated by a compressed and/or connected central band. The cross-sectional geometry of the strip of dunnage is such that one of its transverse dimension (namely its lateral transverse dimension or its width) is greater than its other transverse dimension (namely its non-lateral transverse dimension or its height).

During operation of a cushioning conversion machine, the converting assembly converts the stock material into a strip of dunnage. More specifically, the feeding assembly is activated and the stock material is pulled through the forming assembly and through the feed assembly to form the strip of dunnage. As the stock material is converted, the dunnage strip is urged downstream by the feed assembly and passes through and past a severing zone. The feed assembly is deactivated when the converted length of the strip is such that its leading section corresponds to a desired pad length. The severing assembly is then activated to sever the strip of dunnage into the cushioning pad. After the severing assembly is deactivated, the feed assembly is once again activated and the process is repeated to produce a plurality of cushioning products of desired lengths.

Accordingly, the production rate of a plurality of cushioning pads is determined by the combination of "converting time" and "severing time." Specifically, the pad production rate is dependent on the time it takes the conversion assembly to convert the stock material into sections of desired lengths and the time it takes for the severing assembly to sever these sections into cushioning pads. Pad production rate may be measured by the total number of pads of a certain length produced per unit time. (For example, the number of twenty inch long pads produced in an hour, the number of ten inch pads produced in an hour, etc.)

In the cushioning conversion machines disclosed in U.S. Patent Nos. 4,619,635 and 4,699,609, and in one of the cushioning conversion machines disclosed in U.S. Patent No. 5,123,889, the severing assembly includes a moving blade pivotally attached at one end to the machine frame. To sever the strip of dunnage into a cushioning pad, the moving blade moves in a non-lateral transverse direction from a first position to a second position and then back to the first position. The cushioning conversion machines also each includes a drive assembly including a motor which is operably coupled to the blade to move the blade between the first and second positions. In the cushioning conversion machines disclosed in U.S. Patent No. 4,619,635 and U.S. Patent No. 4,699,609, the drive assemblies includes a pneumatic motor and an electric solenoid motor, respectively, that supply linear motion to the severing assemblies. In the cushioning conversion machine disclosed in U.S. Patent No. 5,123, 889, the drive assembly includes an electric rotary motor that supplies rotational motion and a linkage arrangement that translates the rotational motion into linear motion and supplies the linear motion to the severing assembly.

In another cushioning conversion machine disclosed in U.S. Patent No. 5,123,889, and in the cushioning conversion machines disclosed in U.S. Patent

Application Nos. 08/986,525 and 60/069,393, the severing assembly includes a moving blade slidably attached to the machine's housing or frame. To sever the dunnage strip into a section of a desired length, the blade moves in a non-lateral transverse direction from a first position to a second position and then back to the first position. The cushioning conversion machine further comprises a drive assembly including a motor which is operably coupled to the blade to move the blade between the first and second positions. In each of these machines, the drive assembly is an electric rotary motor that supplies rotational motion which is translated into linear motion to move the blade. In U.S. Patent No. 5,123,889, the motor powers only the severing assembly. In U.S. Patent Applications Nos. 08/986,525 and 60/069,393, the motor powers both the severing assembly and the feeding assembly, and the drive assembly includes a clutch arrangement for the distribution of the power. In the cushioning conversion machine disclosed in U.S. Patent No. 5,674,172, the severing assembly includes a blade which is slidably mounted to the machine's housing or frame. To sever a section of the strip of dunnage into a cushioning pad, the blade is moved in a non-lateral transverse direction from a first position to a second position and back to the first position. The cushioning conversion machine does not include a drive assembly, but rather a handle coupled to the blade via a slotted crank arrangement. The handle is manually moved from a first position to a second position and then back to the first position to move the blade in a corresponding manner. In two of the cushioning conversion machines disclosed in U.S. Patent

Application No. 08/676,681 , the severing assembly includes a blade which is slidably mounted to the machine's housing or frame. In one of these cushioning conversion machines, the blade is a circular cutting wheel. In the other cushioning conversion machine, the blade is a triangular member having an inclined knife edge. In either severing assembly, the blade is moved in the lateral transverse direction to sever a section of the strip of dunnage. The cushioning conversion machines do not include drive assemblies, but rather a handle directly coupled to the blade to manually move it in the lateral transverse direction.

These cushioning conversion machines have achieved considerable commercial success. Nevertheless, especially in high-volume packaging situations, a need remains for the faster production of cushioning pads. Moreover, environmental and other concerns generally create a continuing need for further improvements and modifications of cushioning conversion machines and methods.

SUMMARY OF THE INVENTION

The present invention provides a cushioning conversion machine and method which allows for the faster production of cushioning pads. This faster production is accomplished by the machine's severing assembly being designed to significantly decrease the time it takes to sever a strip of dunnage into a cushioning pad. In comparison to the cushioning conversion machines and methods disclosed in U.S. Patent Nos. 4,619,635; 4,699,609; and 5,123,889 and U.S. Patent Application Nos. 08/986,525 and 60/069,393 (which each include a drive assembly), the severing time is cut substantially in half, thereby significantly increasing the production rate of cushioning pads. In comparison to the cushioning conversion machines and methods disclosed in U.S. Patent No. 5,674,172 and U.S. Patent Application No. 08/676,681 (which each include a manually movable handle), the severing time is also substantially reduced. Accordingly, since the production rate of a plurality of cushioning pads is determined by the combination of the time it takes the conversion assembly to convert the stock material into sections of desired lengths and the time it takes for the severing assembly to sever these sections into cushioning pads, the cushioning conversion machine and method of present invention significantly increases pad production rate. More particularly, the present invention pertains to a cushioning conversion machine comprising a conversion assembly and a severing assembly. The conversion assembly converts sheet-like stock material into a strip of dunnage. The severing assembly includes a blade which moves from a first position to a second position to sever a first section of the strip of dunnage into a first cushioning pad and which moves from the second position back to the first position to sever a succeeding second section of the strip of dunnage into a second cushioning pad. Accordingly, the blade does not need to return to its starting position (i.e., either the first or second position) after the severing of each section of the strip of dunnage thereby allowing a substantial reduction in per-pad severing time.

According to one preferred aspect of the invention, the cushioning conversion machine further comprises a drive assembly. The drive assembly includes a motor that is operably coupled to the blade to move it between the first and second positions. Preferably, the drive assembly provides rotational motion which is translated into linear motion.

According to an additional or alternative preferred aspect of the invention, the blade moves in a transverse direction as it travels between the first position and the second position. The transverse travel direction of the blade corresponds to the lesser transverse dimension of the strip of dunnage. The movement of the blade in this transverse direction (as opposed to the other transverse direction) further adds to the reduction of per-pad severing time. The blade is preferably part of a moving blade mechanism that additionally comprises a carriage. The carriage is slidably mounted to the machine's housing and the blade is fixedly mounted to the carriage. The severing assembly preferably additionally comprises a motion-transferring mechanism which transfers motion to the moving blade mechanism from, for instance, the drive assembly. The motion- transferring mechanism is preferably coupled to the carriage by, for example, a pair of crank arms and moves the carriage between first and second positions thereby moving the blade between its first and second positions. If the cushioning conversion machine includes a drive assembly and the drive assembly provides rotational motion, the motion-transferring mechanism translates the rotational motion into linear motion. In such a situation, the motion-transferring mechanism preferably includes a rotating shaft that is operably coupled to the drive assembly. Preferably, one-half revolution of this shaft moves the blade between the first and second positions.

A cushioning conversion method according to the present invention comprises the steps of supplying a sheet-like stock material, converting the sheet-like stock material into a strip of dunnage, and severing the strip of dunnage into cushioning pads of desired lengths. More particularly, the stock material is converted until a first leading section of the strip of dunnage corresponds to a first desired pad length and then the blade is moved from the first position to the second position to sever the first section into a first cushioning pad. Next, the stock material is converted until a second leading section of the strip of dunnage corresponds to a second desired pad length and then the blade is moved from the second position back to the first position to sever the second section into a second cushioning pad.

The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims. The following description and annexed drawings set forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but a few of the various way in which the principles of the invention may be employed.

DRAWINGS Figure 1 is a side view of a cushioning conversion machine according to the present invention, the machine being shown with some portions of its housing removed to reveal certain interior components.

Figure 2 is a downstream end view of the cushioning conversion machine. Figure 3 is a side elevational view, partially in section, of the cushioning conversion machine looking in the direction of arrows 3-3 in Figure 2. Figure 4 is another side elevational view, partially in section, looking in the direction of arrows 4-4 in Figure 2.

Figure 5 is yet another side elevational view, partially in section, looking in the direction of arrows 5-5 in Figure 2, a moving blade of the machine's severing assembly being shown in a first upper position.

Figure 6 is a side elevational view, partially in section, which is the same as Figure 5 except that the moving blade is shown in a second lower position.

Figures 7A-7D are schematic views of the operation of the cushioning conversion machine. Figure 8 is a perspective view of a strip of cushioning produced by the cushioning conversion machine.

DETAILED DESCRIPTION Referring now to the drawings in detail, and initially to Figure 1, a cushioning conversion machine 10 according to the present invention is shown. The cushioning conversion machine 10 comprises a conversion assembly 12 which converts a sheetlike stock material into a strip of dunnage, a stock supply assembly 14 which supplies the stock material to the conversion assembly 12, and a severing assembly 16 which severs the strip of dunnage. The machine 10 also comprises a drive assembly 18 which provides power to the severing assembly 16 and which, in the illustrated embodiment, also provides power to the conversion assembly 12.

The cushioning conversion machine 10 further comprises a housing 22 which encloses and/or supports the conversion assembly 12, the stock supply assembly 14, and the severing assembly 16. The illustrated cushioning conversion machine 10 has a modular construction whereby its housing 22 includes a first housing section 24 and a second housing section 26. A modular cushioning conversion machine construction of this general type, and the advantages thereof, are described in detail in U.S. Patent No. 5,674,172. However, other modular and non-modular housing constructions are possible with, and contemplated by, the present invention. The first housing section 24 is in the form of an outer or external shell, the geometry of which is best described by referring to the drawings. The housing section 24 is comprised of a base 30 and a hinged cover 32. A bottom wall of the base 30 defines an inlet opening (not specifically shown in the drawings) and the downstream edges of the base 30 and the cover 32 together define an outlet opening (also not specifically shown in the drawings). The first housing section 24 is similar to, if not the same as, the first housing section shown and described in U.S. Patent No. 5,674,172. (The first housing section in this patent is referred to as the rear unit, the shaping unit and/or the former.)

Referring now additionally to Figures 2-6, the second housing section 26 has a generally box-like geometry and comprises a pair of side plates 36, a top plate 38, a cross plate 40, a bottom plate 42, a pair of upstream plates 44, a pair of downstream plates 46, and a platform plate 50. The plates 36, 38, 40, 42, 44, 46 and 50 each have a generally planar geometry, that is its width and length dimensions are much greater than its thickness dimension. The plates are assembled together (i.e., welded, bolted) or may be formed in one piece. Although not shown in the drawings, the second housing section 26 may also include a thin cover made of, for instance, plastic or sheet metal. The side plates 36 and top plate 38 each have a rectangular configuration. The side plates 36 are vertically oriented and positioned in a plane parallel to the upstream- downstream direction. The top plate 38 is horizontally oriented and positioned in a plane parallel to the upstream-downstream direction. The side plates 36 are spaced apart to generally define the lateral sides of the second housing section 26. The top plate 38 is attached to (and extends between) downstream regions of the respective upper edges of the side plates 36. Bearing openings 52 are provided in the side plates 36 to accommodate a component of the conversion assembly 12 (shown in Figure 1), namely the ends of a rotating shaft 84, introduced below.

The cross plate 40 has a rectangular configuration. The plate 40 is vertically oriented, positioned in a plane perpendicular to the upstream-downstream direction, and extends between lower portions of the side plates 36. More specifically, upper sections of the cross plate's lateral edges are attached to lower intermediate sections of the side plates 36. In this manner, lower sections of the cross plate 40 extend below the lower edges of the side plates 36. A large notch 54 is provided in an intermediate (but not exactly central) region of the upper edge of the cross plate 40 to accommodate a component of the conversion assembly 12, namely a rotating feed member 82 introduced below. A vertically extending slot 56 is provided in the right-hand side of the cross plate 40 to accommodate a component of the drive assembly 18, namely a belt 152 introduced below.

The bottom plate 42 has a rectangular configuration, is horizontally oriented and is positioned in a plane parallel to the upstream-downstream direction. The plate 42 is attached to the upstream surface of the bottom edge of the cross plate 40 and longitudinally extends upstream therefrom. The bottom plate 42 does not laterally extend across the width of the cross plate 40, but instead is offset to one side thereof.

The upstream plates 44 each have a roughly triangular configuration. More particularly, the upstream plates 44 each are in the shape of a right isosceles triangle having its two non-perpendicular corners removed. The plates 44 are vertically oriented and positioned in a plane parallel to the upstream-downstream direction. The upstream plates 44 are attached to the upstream surface of the cross plate 40 on either side of the bottom plate 42.

The downstream plates 46 are each generally rectangular in configuration, vertically oriented and are each positioned parallel to the upstream-downstream direction. The plates 46 are attached to the downstream surface of the cross plate 40 and longitudinally project downstream therefrom. They are not symmetrically positioned relative to the lateral center line of the cross plate 40, but instead are spaced apart a certain distance to accommodate the severing assembly 16 and/or the drive assembly 18. Bearing openings 58 are provided in each of the downstream plates 46 to accommodate a component of the severing assembly 16, namely a rotating shaft 118 introduced below.

The platform plate 50 is generally rectangular in configuration. The plate 50 is horizontally oriented and positioned in a plane parallel to the upstream-downstream direction. The platform plate 50 is positioned just above the upper edge of the downstream plates 46 (and may rest thereon) and extends downstream from the cross plate 40. A laterally extending slot 62 is provided in the platform plate 50 to accommodate a component of the severing assembly 16, namely the lower edge 114 of a moving blade 106 introduced below. Referring back to Figure 1 , the conversion assembly 12 includes a forming assembly 70 and a feeding assembly 72. The forming assembly 70 is supported by, and/or enclosed in, the first housing section 24. The feeding assembly 72 is supported by, and/or enclosed in, the second housing section 26. During the conversion process, the forming assembly 70 forms the stock material by inwardly turning its lateral regions and the feeding assembly 72 feeds the stock material through the forming assembly 70. The forming assembly 70 includes a shaping chute 74 and a former member 76 which, in the illustrated embodiment, are the same as or similar to the analogous components disclosed in U.S. Patent No. 5,674^172. The shaping chute 74 and the former member 76 coact to ensure proper shaping and forming of the stock material. More particularly, the former member 76 is operative to guide the central region of the stock material along the bottom wall of the shaping chute 74 for controlled inward turning of its lateral regions. Referring again to Figures 2-6, the feeding assembly 72 comprises rotatable, generally loosely meshed gear-like members or rotating feed members 80 and 82. The upper rotating feed member 80 (or the "drive" wheel) is fixedly attached to a shaft 84 which is rotatably driven by the drive assembly 18. The opposite ends of the rotating shaft 84 extend through the bearing openings 52 in the side plates 36 and are attached to bearing mounting caps 88. In this manner, the shaft 84 is rotatably mounted to the machine's housing 22, and more particularly to the second housing section 26.

The lower rotating feed member 82 (or the "idler" wheel) is rotatably journaled on a shaft 86 which is non-rotatably attached to the machine's housing 22, and more particularly the second housing section 26, in a suitable manner. Preferably, this attachment includes a biasing system which resiliently urges the rotating feed member 82 towards the rotating feed member 80 to hold them in a meshed relationship with the stock material therebetween.

The rotating feed members 80 and 82 are longitudinally positioned just upstream of the cross plate 40. The rotating feed members 80 and 82 are laterally positioned to engage a central region of the strip of stock material and a lower region of the feed member 82 passes through the notch 54 in the cross plate 40. The rotating feed members 80 and 82 may be of the type disclosed in U.S. Patent No. 4,968,291 which coin and perforate the central band. Alternatively, the rotating feed members 80 and 82 may be of the type disclosed in International Publication Number WO 96/40493 which function to interlock the central band by forming a row of tabs. (See Figure 8.) (This patent and the invention disclosed in this publication are assigned to the assignee of the present application and their entire disclosures are hereby incorporated by reference.) Referring again to Figure 1 , the stock supply assembly 14 is supported by, and partially enclosed in, the first housing section 24. The illustrated stock supply assembly 14 includes a pair of laterally spaced apart mounts in the form of brackets 92 for supporting the stock roll. The brackets 92 each have a J-shape lower distal portion. This lower portion of the bracket 92 forms an upwardly opening slot for nested receipt of the ends of a stock roll holder (such as a bar or rod) on which a stock roll (not shown) may be rotatably supported. The proximate upper portion of each stock roll bracket 92 is generally L-shape (in cross section) and configured for wrap-around attachment to the corners adjoining the side walls to the upstream end wall of the base 30 of the first housing section 24. Similar brackets are described in more detail in U.S. Patent No. 5,764,172.

The illustrated stock supply assembly 14 further comprises an entry guide member 94 and separating members 96, preferably both in the form of the rollers described in U.S. Patent No. 5,764,172. The entry guide member 94 provides a non- varying point of entry for the stock material into the forming assembly 70 regardless of the diameter of the roll of stock material. The separating members 96 separate the respective plies of the stock material. (As is explained in more detail below, the preferred stock material has multiple plies or layers.) The members 94 and 96 are supported by and extend between upstream portions of the side walls of the base 30 of the first housing section 24. The stock material passes from the stock roll supported by the brackets 92, through the inlet opening in the bottom wall of the base 30, over the entry guide member 94, and through the separating members 96.

Referring back to Figures 2-6, the severing assembly 16 comprises a moving blade mechanism 100 and a motion-transferring mechanism 102. The moving blade mechanism 100 contains the "cutting" component(s) of the severing assembly 16. The motion-transferring mechanism 102 transfers motion from the drive assembly 18 to the moving blade mechanism 100. Both of the mechanisms 100 and 102 are supported by, and/or enclosed in, the second housing section 26.

The moving blade mechanism 100 comprises a carriage 104, a blade 106 and a pair of guide rods 108. The carriage 104 has a rectangular column-like geometry (laterally extending) and includes a pair of non-symmetrical vertical channels 110. The blade 106 is fixedly mounted to an upstream surface of the carriage 104 and has both an upper knife edge 112 and a lower knife edge 114 that extend above and below, respectively, the carriage's top and bottom sides. The edges 112 and 114 are preferably parallel to each other and inclined relative to the horizontal. The guide rods 108 extend vertically between, and are fixedly attached to, the top plate 38 and the platform plate 50. The guide rods 108 slidingly extend through the carriage channels 110 whereby the carriage 104, and thus, the bla^'de 106, are mounted for linear sliding movement on the guide rods 108. (Compare Figures 5 and 6.)

The motion-transferring mechanism 102 comprises a rotating shaft 118, a pair of hubs 120, a pair of crank arms 122 and a pair of connecting rods 124. The rotating shaft 118 extends through the bearing openings 58 in the downstream plates 46. In any event, the shaft 118 is rotatably mounted relative to the machine's housing 22.

The ends of the rotating shaft 118 extend beyond the downstream plates 46 and the hubs 120 are mounted thereon. The crank arms 122 are each connected to a respective hub 120 whereby they rotate with the shaft 118. The connecting rods 124 are joumaled at one end to the crank arms 122 and extend upward therefrom adjacent the opposite lateral ends of the platform plate 50. The opposite ends of the connecting rods 124 are pivotally connected to respective ends of the carriage 104. In this manner, the carriage 104 and the blade 106 attached thereto are reciprocally moved up and down on the guide rods 108 as the shaft 118 is rotated. (Compare Figures 5 and 6.) When the carriage 104 and the blade 106 are in the lowermost position, the blade's lower knife edge 114 is received within the slot 62 of the platform plate 50.

As is explained in more detail, when certain components of the drive assembly 18 are activated and/or engaged (namely a motor 138 and a clutch 140 introduced below), the moving blade mechanism 100 moves the blade 106 between a first upper position and a second lower position. (Compare Figures 5 and 6.) The vertical plane in which the blade 106 travels as it moves from the first position to the second position may be defined as a severing zone 126. The severing zone 126 is longitudinally aligned with the rotating feed members 80 and 82 of the feeding assembly 72. The severing zone 126 is laterally located between the guide rods 108.

The severing assembly 16 may also comprise stationary blades 130 and 132 that coact with the blade 106 during the severing process in a shear-like fashion. The top stationary blade 130 is mounted on the lower end of a joist member 134 which projects downwardly from the top plate 38. The bottom stationary blade 132 is mounted on the upper end of a joist member 136 which projects upwardly from the platform plate 50. The joist members 134 and 136 position the blades 130 and 132 at the upper and lower edges of the severing zone 126.

As was indicated above, the drive assembly 18 provides power to the severing assembly 16. The preferred drive assembly 18 comprises a motor 138, a clutch 140 (mounted to the machine's housing by a plate 142), and a motion-transferring mechanism 144. The clutch 140 is selectively engageable with the severing assembly 16, or more particularly its rotating shaft 118. The motion-transferring mechanism 144 transfers motion from the motor 138 to the clutch 140.

The motor 138 is preferably an electric rotary motor which may be mounted to the bottom plate 42 of the second housing section 26 by, for example, bolting it thereto. The motor 138 has an output shaft 146 and a speed reducer may be incorporated between the motor 138 and the output shaft 146. Such a speed reducer may or may not be necessary depending on whether the output speed and torque of the selected motor 138 is already appropriate and/or whether certain gear train or other motion- transferring arrangements are employed.

The clutch 140 is selectively engageable with the rotating shaft 118 of the severing assembly 16. The clutch 140 may be a wrap spring clutch, an electromagnetic clutch, or any other suitable clutch arrangement which allows the shaft 118 to be selectively rotated in half-revolution increments. In the illustrated embodiment, the non-rotating portions of the clutch 140 are mounted to the plate 142 that is laterally positioned intermediate (but not centrally) between the pair of downstream plates 46. In any event, the mounting of the clutch 140 to the machine's housing section 26 is done in such a manner that the output portion of the clutch 140 may be drivingly connected to the shaft 118 when the clutch is in an engaged condition.

The motion-transferring mechanism 144 transfers rotational motion from the motor output shaft 146 to certain interior components of the clutch 140. Thus, the motion-transferring mechanism 144 may be any suitable mechanism capable of this transfer. For example, the motion-transferring mechanism 144 may comprise a chain and sprocket system, a spur gear system, or a pulley system.

In the illustrated embodiment, the motion-transferring mechanism 144 is a pulley system comprising pulleys 148 and 150 and a belt 152. The pulley 148 is coupled to the motor output shaft 146 and the pulley 150 is coupled to the clutch 140. The belt 152 extends between the pulleys 148 and 150 and passes through the slot 56 in the cross plate 40. The illustrated motion-transferring mechanism 144 further includes an idler pulley 154 mounted to either the adjacent side plate 36 or the adjacent upstream plate 44 of the second housing section 26. When the motor 138 is operating (i.e., when its output shaft 146 is rotating), the motion-transferring mechanism 144 in turn rotates the interior components of the clutch 140. When the clutch 140 is engaged with the shaft 118, the shaft 118 is rotated for half a revolution. The hubs 120 in turn are rotated a half of a revolution thereby moving the crank arms 122, the connecting rods 124, and the carriage 104. In this manner, the motion transferring mechanism 102 of the severing assembly 16 moves the blade 106 from an upper position to a lower position. (Compare Figure 5 to Figure 6.) Alternatively, the motion-transferring mechanism 102 of the severing assembly 16 moves the blade 106 from the lower position back to the upper position. (Compare Figure 6 to Figure 5.) In the illustrated embodiment shown in Figure 1, the drive assembly 18 also provides power to the conversion assembly 12, or more particularly the feeding assembly 72. However, cushioning conversion machines and methods wherein the conversion assembly is provided with power in a different manner is certainly possible with, and contemplated by, the present invention. For example, the cushioning conversion machine 10 could include another electric motor which directly or indirectly (i.e., through a clutch and/or a motion-transferring mechanism) supplies rotational motion to the feeding assembly 72.

In any event, the illustrated drive assembly 18 further comprises a clutch 156 which is selectively engageable with the feeding assembly 72 and a motion-transferring mechanism 158 which transfers motion from the motor 138 to the clutch 156. The clutch 156 may be a wrap spring clutch, an electromagnetic clutch, or any other suitable clutch or clutch-like arrangement which is selectively engageable with the drive shaft 84 of the feeding assembly 72. Although not particularly shown in the drawings, the non- rotating portions of the clutch 156 would be suitably mounted to the machine's housing, such as by a plate or bracket secured to the adjacent side plate 36.

The motion-transferring mechanism 158 may comprise a chain and sprocket system, a spur gear system, or a pulley system. In the illustrated embodiment, it is a pulley system comprising a pulley 160 coupled to the motor shaft 146, a pulley 162 coupled to the clutch 156, and a belt 164 therebetween. The illustrated motion- transferring mechanism 158 further includes an idler pulley 166 mounted to the adjacent side plate 36.

When the motor 138 is operating (i.e., when its shaft 146 is rotating), the motion-transferring mechanism 158 in turn rotates the interior components of the clutch 156. When the clutch 156 is engaged, it rotates the shaft 84 thereby rotating the upper feed member 80. The upper feed member 80 in turn rotates the lower feed member 82 to feed, or more particularly pull, the stock material through the cushioning conversion machine. Turning now to Figures 7A-7E, the operation of a cushioning conversion machine according to the present invention is schematically shown. During this operation, the stock material is converted into a strip of dunnage 170. More specifically, the feeding assembly 72 is activated and the stock material is pulled through the forming assembly 70 and through the feeding assembly 72 to form the strip 170. As the stock material is converted, the strip of dunnage 170 is urged downstream by the feeding assembly 72. More particularly, the strip 170 passes through and past the severing zone 126. The feeding assembly 72 is deactivated (i.e., the clutch 156 is disengaged) when the converted length of the strip 170 is such that a first leading section 172 corresponds to a first desired pad length. More particularly, the trailing edge of the first section 172 will be longitudinally aligned with the severing zone 126. The severing assembly 16 is then activated to move the blade 106 from its first upper position to its second lower position thereby severing the first section 172 of the strip 170 into a first cushioning pad 174. The conversion assembly 12 then converts more of the stock material so that a second section 176 of the strip 170 corresponds to a second desired pad length that may or may not be the same as the first desired pad length. The severing assembly 16 is then activated to move the blade 106 from its second lower position to its first upper position thereby severing the second section 1 6 of the strip 170 into a second cushioning pad 178.

The alternate activation of the conversion assembly 12 and the severing assembly 16 is continuously repeated to produce a plurality of pads of desired lengths. Because the blade 106 does not need to return to its starting position (i.e., either the first upper position or the second lower position), after the severing of each section of the strip 170, the severing time is cut substantially in half when compared to prior art cushioning conversion machines and methods having driven severing assemblies, such as those disclosed in U.S. Patent Nos. 4,619,635, 4,699,609, 5,123,889, and U.S. Patent Application Nos. 08/986,525; and 60/069,393.

It should be noted at this point that although the cushioning conversion machine preferably includes a drive assembly for moving the blade 106 between the first and second positions, a cushioning conversion machine having a manually operated severing assembly is possible with, and contemplated by, the present invention. In such a cushioning conversion machine, a handle could be operably coupled to the blade 106 to move it from a first position to a second position to sever a first section 172 of the strip of dunnage 170 and to move it from the second position back to the first position to sever a second section 176 of the strip of dunnage. Again, because the blade 106 does not need to return to its starting position (/^*.e., either the first upper position or the second lower position), after the severing of each section of the strip 170, the severing time is cut substantially in half when compared to prior art cushioning conversion machines and methods having manually operated severing assemblies, such as that disclosed in U.S. Patent No. 5,674,172.

It should also be noted at this point that, although in the preferred severing assembly 16 the blade 106 moves in a guillotine-like manner, other designs are possible with and contemplated by the present invention. For example, blade a having one end pivotally mounted to the machine's housing could move in a scissors-like fashion between first and second position. More specifically, the distal end of such a blade would move from a first position to a second position to sever a first section of the strip of dunnage into a first cushioning pad and would move from the second position back to the first position to sever a second section of the strip of dunnage into a second cushioning pad.

Accordingly, since the production rate of cushioning pads is determined by the combination of the time it takes a conversion assembly to convert the stock material into sections of desired lengths and the time it takes for a severing assembly to sever these sections into cushioning pads, a cushioning conversion machine and method according to the present invention significantly increases pad production rate.

Referring now to Figure 8, in the preferred conversion assembly 12 illustrated in Figure 1 , the forming assembly forms the stock material into a strip having lateral pillowlike portions and a central portion therebetween. The feeding assembly connects and/or compresses the central portion to join together overlapped lateral edges of the stock material. As such, the converted strip of dunnage 170 has lateral pillow-like portions 180 separated by a central band 182 having a plurality of tabs 184. Thus, when the preferred conversion assembly 12 converts the stock material into the strip of dunnage 170, the strip of dunnage 170 has at least one pillow-like portion 180. In any event, the density of the converted strip of dunnage 170 and/or the pillow-like portion(s)180 is substantially less than the density of the stock material.

The cross-sectional geometry of the strip of dunnage 170 is such that one of its transverse dimension T., (namely its lateral transverse dimension or width) is greater than its other non-lateral transverse dimension T₂ (namely its non-lateral transverse dimension or its height). For example, with the preferred conversion assembly 12 illustrated in Figure 1 , the strip of dunnage is approximately seven to nine inches wide and approximately two to four inches high. Thus, the strip of dunnage 170 has one transverse dimension T greater than its other transverse dimension T₂. When the preferred severing assembly 16 is used, the blade 106 moves in a transverse direction as it travels between the first position and the second position. This transverse direction of blade travel corresponds to the lesser transverse dimension T₂ of the strip of dunnage 170. The movement of the blade 106 in this direction (rather than the other transverse direction T,) further adds to the reduction of severing time when compared, for instance, to cushioning conversion machines in which the blade travels in the other traverse direction such as that disclosed in U.S. Patent Application No. 08/676,681. As explained above, a reduction in severing time results in an increase in pad production rate.

In the preferred embodiment of the invention, the stock material comprises superimposed plies (i.e., webs, layers) of biodegradable, recyclable and reusable paper rolled onto a hollow cylindrical tube. More specifically, the preferred stock material is a roll of two or three superimposed webs or layers of biodegradable, recyclable and reusable thirty-pound or fifty-pound Kraft paper, for example. The roll is preferably between twenty-eight and thirty inches wide and usually about four hundred fifty feet long. The preferred cushioning conversion machine will convert the preferred roll of stock material into cushioning pads 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. One may now appreciate the present invention provides a cushioning conversion machine and method wherein the severing assembly or step is designed to decrease severing time and thereby increase pad production rate. Although the invention has been shown and described with respect to a certain preferred embodiment, it is obvious that equivalent alternations and modifications will occur to others skilled in the art upon a reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications.

Claims

1. A cushioning conversion machine (10) comprising: a conversion assembly (12) which converts a sheet-like stock material into a strip of dunnage (170) having at least one pillow-like portion (180); a severing assembly (16) including a blade (106) which moves from a first position to a second position to sever a first section (172) of the strip of dunnage (170) into a first cushioning pad (174) and which moves from the second position back to the first position to sever a second section (176) of the strip of dunnage (170) into a second cushioning pad (178); and a drive assembly (18) including a motor (138) operably coupled to the blade (106) to move the blade (106) between the first and second positions.

2. A cushioning conversion machine (10) as set forth in the preceding claim wherein the blade (106) includes a first knife edge (112) and a second knife edge (114).

3. A cushioning conversion machine (10) as set forth in the preceding two claims wherein the blade (106) is part of a moving blade mechanism (100) and wherein the severing assembly (16) additionally comprises a motion-transferring mechanism (102) which transfers motion from the drive assembly (18) to the moving blade mechanism (100).

4. A cushioning conversion machine (10) as set forth in the preceding claim wherein the moving blade mechanism (100) additionally comprises a carriage (104) slidably mounted to the machine's housing (22) and to which the moving blade (106) is fixedly mounted and wherein the motion-transferring mechanism (102) is coupled to the carriage (104) to move the carriage (104) between first and second positions thereby moving the blade (106) between its first and second positions.

5. A cushioning conversion machine (10) as set forth in the preceding claim wherein the motion-transferring mechanism (102) comprises a pair of crank arms (122) coupled to opposite lateral ends of the carriage (104).

6. A cushioning conversion machine (10) as set forth in any of the preceding claims wherein the severing assembly (16) further comprises a first stationary blade (130) positioned to interact with the moving blade (100) when it is in the first position and a second stationary blade (132) positioned to interact with the moving blade (100) when it is in the second position.

7. A cushioning conversion machine (10) as set forth in claim 3 or any preceding claim depending therefrom wherein the drive assembly (18) provides rotational motion and wherein the motion-transferring mechanism (102) translates the rotational motion to linear motion.

8. A cushioning conversion machine (10) as set forth in the preceding claim wherein the motion-transferring mechanism (102) includes a rotating shaft (118) operably coupled to the drive assembly (18) and wherein one-half rotation of the shaft (118) moves the blade (106) between the first and second positions.

9. A cushioning conversion machine (10) as set forth in any of the preceding claims wherein the conversion assembly (12) converts the sheet-like stock material into the strip of dunnage (170) in such a manner that the strip of dunnage (170) has two pillow-like portions (180) and a central band (182) therebetween.

10. A cushioning conversion machine (10) as set forth in any of the preceding claims wherein the conversion assembly (12) converts the sheet-like stock material into the strip of dunnage (170) in such a manner that one transverse dimension (T^ of the strip of dunnage (170) is greater than another transverse dimension (T₂) of the strip of dunnage (170) and wherein the blade (106) moves in a transverse direction as it travels between the first position and the second position, this transverse direction corresponding to the lesser transverse dimension (T₂) of the strip of dunnage (170).

1 1. A cushioning conversion machine (10) comprising a conversion assembly (12) which converts a sheet-like stock material into a strip of dunnage (170) having one transverse dimension (T,) greater than another transverse dimension (T₂) and a severing assembly (16) which severs the strip of dunnage (170) into cushioning pads (174, 178) of desired lengths; the severing assembly (16) including a blade (106) which moves from a first position to a second position to sever a first section (172) of the strip of dunnage (170) into a first cushioning pad (174) and which moves from the second position back to the first position to sever a second section (176) of the strip of dunnage (170) into a second cushioning pad (178); and wherein the blade (106) moves in a transverse direction as it travels between the first position and the second position, this transverse direction corresponding to the lesser transverse dimension (T₂) of the strip of dunnage (170).

12. A cushioning conversion machine (10) as set forth in the preceding claim wherein the blade (106) includes a first knife edge (112) and a second knife edge (114).

13. A cushioning conversion machine (10) as set forth in the preceding two claims wherein the blade (106) is part of a moving blade mechanism (100) and wherein the severing assembly (16) additionally comprises a motion-transferring mechanism (102) which transfers motion to the moving blade mechanism (100).

14. A cushioning conversion machine (10) as set forth in the preceding claim wherein the moving blade mechanism (100) additionally comprises a carriage (104) which is slidably mounted the machine's housing (22) and to which the moving blade (106) is fixedly mounted and wherein the motion-transferring mechanism (102) is coupled to the carriage (104) to move the carriage (104) between first and second positions thereby moving the blade (106) between its first and second positions.

15. A cushioning conversion machine (10) as set forth in the preceding claim wherein the motion-transferring mechanism (102) comprises a pair of crank arms (122) coupled to opposite lateral ends of the carriage (104).

16. A cushioning conversion machine (10) as set forth in the preceding claim wherein the motion-transferring mechanism (102) includes a rotating shaft (118) coupled to the crank arms and wherein one-half revolution of the shaft (118) moves the carriage (104) between its first and second positions.

17. A cushioning conversion machine (10) as set forth in any of claims 1 1-16 wherein the severing assembly (16) further comprises a first stationary blade (130) positioned to interact with the moving blade (100) when it is in the first position and a second stationary blade (132) positioned to interact with the moving blade (100) when it is in the second position.

18. A cushioning conversion machine (10) as set forth in any of claims 1 1-17 wherein the conversion assembly (12) converts the sheet-like stock material into the strip of dunnage (170) in such a manner that the strip of dunnage (170) has two pillowlike portions (180) and a compressed central band (182) therebetween.

19. A cushioning conversion method comprising the steps of supplying a sheet-like stock material, converting the sheet-like stock material into a strip of dunnage (170) and severing the strip of dunnage (170) into cushioning pads, wherein said converting and severing steps include: converting the stock material until a first leading section (1 2) of the strip of dunnage (170) corresponds to a first desired pad length; moving a blade (106) from a first position to a second position to sever the first section (172) into a first cushioning pad (174); converting the stock material until a second leading section (176) of the strip of dunnage (170) corresponds to a second desired pad length; moving the blade (106) from the second position back to the first position to sever the second section (176) into a second cushioning pad (178); wherein said steps of moving the blade (106) are accomplished by a motor (138) operably coupled to the blade (106) to move the blade (106) between the first and second positions.

20. A cushioning conversion method comprising the steps of supplying a sheet-like stock material, converting the sheet-like stock material into a strip of dunnage (170) having one transverse dimension (T^ greater than another transverse dimension (T₂) and severing the strip of dunnage (170) into cushioning pads of desired lengths, wherein said converting and severing steps include: converting the stock material until a first leading section (172) of the strip of dunnage (170) corresponds to a first desired pad length; moving a blade (106) from a first position to a second position to sever the first section (172) into a first cushioning pad (174); converting the stock material until a second leading section (176) of the strip of dunnage (170) corresponds to a second desired pad length; moving the blade (106) from the second position back to the first position to sever the second section (176) into a second cushioning pad (178); wherein the blade (106) moves in a transverse direction as it travels between the first position and the second position, this transverse direction corresponding to the lesser transverse dimension (T₂) of the strip of dunnage (170).

21. A cushioning conversion method as set forth in claim 20 wherein said steps of moving the blade (106) are accomplished by a motor (138) operably coupled to the blade (106) to move the blade (106) between the first and second positions.

22. A cushioning conversion method comprising the steps of supplying a sheet-like stock material and using the cushioning conversion machine (10) of any of claims 1-18 to convert the stock material into a plurality of cushioning pads.

23. A method as set forth in any of the preceding method claims wherein the step of supplying the sheet-like stock material comprises supplying stock material that is biodegradable, recyclable and made from a renewable resource.

24. A method as set forth in any of the preceding method claims wherein the step of supplying the stock material comprises supplying stock material that is paper.

25. A method as set forth in any of the preceding method claims wherein the step of supplying the stock material comprises supplying stock material that is multi-ply paper.

26. A method as set forth in any of the preceding method claims wherein the step of supplying the stock material comprises supplying stock material that is thirty pound Kraft paper or fifty-pound Kraft paper.

27. A method as set forth in any of the preceding method claims wherein the step of supplying the stock material comprises supplying stock material that is approximately twenty-seven to thirty inches wide.