Lifting device for stripping and blanking operations

A deflectable lifting device can be mounted to a support form, work surface or other member of a material conveyance system. According to embodiments, the deflectable lifting device can have a base that mounts into the support, and a bendable arm arranged in the pathway of a material conveyance system, such as a paper stripping or paper blanking work station. When a sheet or web of material travels over the deflectable lifting device, the bendable arm can bend and deflect downwards, but still contact the sheet or web with a gently humped or arcuate portion, providing a small margin of elevation or lift to the sheet or web. The sheet or web can therefore be elevated above edges, holes, or other obstructions in the pathway that could jam or snag the delivery of the material. The deflectable lifting device can comprise an arcuate portion or head over which the sheet or web can slide in a bearing fashion.

FIELD

The present teachings relate to the field of paper or other fiber product manufacturing, and more particularly to a device and method for preventing jamming or snagging of paper, cardboard, or other sheets or webs of conveyed material as they are transferred across presses, dies, punches, or other paper-cutting or paper-forming equipment.

BACKGROUND

Packaging, stationary, and other paper-based products are generally manufactured using sheets of raw paper stock or other material that are drawn across presses, dies, punches, or other paper-cutting or paper-forming equipment. Beverage and other cartons, containers, playing cards, signs, placards, corrugated boxes, and other paper or fiber-based or other products are generally formed by contacting a sheet or web of raw material with a punch or die when stripping-out desired areas of material. Such products can also be formed by contacting the sheet or web with a cutting or fold-making blade when generating blanks out of the sheet.

The first process of stripping out holes or sections from the larger piece of material, which leaves a shaped hole and a desired perimeter or outline in the intact paper or other material, is generally referred to as stripping. The second process of cutting or punching a desired shape or section of the sheet entirely out of the sheet and dropping away the removed portion as the desired product, is generally referred to as blanking. In both stripping and blanking operations, the raw feedstock can be in the form of paper, cardboard, plastic, fibrous, or other material, which is conveyed over a working area. The working area can generally include a flat cutting surface or hollow female blanking area over which a blank stock can be contacted with a blade, punch, or other working tool. The sheets are conveyed through work areas on support frames, for example, wooden, metal, or other support frames, which can be sized to conform to the input sheets. The sheets can be conveyed across the stripping or blanking areas using belt drives, linear motors, or other sources of mechanical driving force.

Known stripping and blanking configurations suffer from a number of drawbacks. One drawback can be that the waste portion of the sheet which has been stripped or blanked can jam or snag in the support frame at different points. This can happen, for example, because the sheet dips or sags into open recesses of a blank or die area, catching edges of material on exposed edges in those areas. When a sheet, a knockout, or other waste material produced from a punched or cut sheet, jams in the conveyance path, the machinery may have to be stopped and an operator may need to remove the cut blanks or waste material. Furthermore, the next sheet in the conveyance path can jam against the blocked waste, possibly ruining the next sheet as well.

To attempt to reduce these and other types of material jam-ups, a thin metal element can be attached to the bridge of the work area frame between the recesses, so that a male blanking part, die, or other working tool can be pressed. This lifting type of support is sometimes called a bridge rule. A bridge rule can be comprised of, for example, a plywood stud or other support beam, which supports a sheet of material as it is conveyed over the bridge. However, attaching, orienting, leveling, and maintaining a bridge rule can be time consuming. Metal bridge rules can be subject to damage caused by bending, metal fatigue, misalignment on the beam, or accidental detachment.

Often a male stripping, blanking, or other member or working tool can apply pressure against a sheet that is only supported at the margins, thus causing the sheet to sag. This can cause the tool to partially or totally fail to strip, punch, blank, or otherwise manipulate the sheet when it strikes an unsupported or sagging area. In the case of blanking operations, the blank can fail to separate from the surrounding skeleton (or waste material) and drop free. Jams and hang-ups in the material supply path and incomplete or faulty stripping and blanking operations can waste valuable operator time and effort, cause lost costs from manufacturing downtime, and result in loss of potentially recoverable material. A need exists to eliminate these and other drawbacks in the art.

SUMMARY

According to various embodiments, the present teachings relate to a mechanical device that can be attached or mated to a material conveyance system to lift a transferred sheet of paper or other material, and in one regard elevate the sheet above the edges of blanks, frames, or other edges and/or recesses to prevent, resist, or reduce accidental jamming of the conveyance path. In some embodiments, the deflectable lifting device can comprise an elastically deformable member formed with a generally curved, extended bendable arm, which is formed with a securing base. The securing base can be formed, for example, in a generally rectangular shape for insertion into a matching mounting slot in the frame of a material conveyance system. According to various embodiments, the base of the deflectable lifting device can be formed with retaining nibs, ribs, teeth, notches, or other protrusions or recesses which create a friction fit or snap-in fit in the mounting slot of the frame.

According to various embodiments, the base can be formed with one or more vertical relief slits, which can permit transverse flex in the material of the base, for example, to create a compression or friction fit in the mounting slot and/or to relieve stress or stresses on the base under load. In some embodiments, the base can be fixedly secured into the slot of, or otherwise affixed to, the frame or other member, using adhesives, magnets, bolts, screws, coupling devices, or other mounting, fastening, or attachment techniques. According to various embodiments, the deflectable lifting device can be mounted or oriented in the direction of the sheet or web path, with the bendable arm positioned parallel to the direction of sheet travel. In some embodiments, when a sheet of paper or other material is conveyed through the work area, it can come into contact with the bendable arm, and the leading edge or distal tip of the bendable arm can deflect downwardly under the applied force of the tools or materials used in stripping or blanking operations, for example, a speed bar, presser bar, or other tool, or, in the case of a female stripper implementation, foam. In some embodiments, the bendable arm can be deflected into an elevated position with respect to the bridge, frame, or other support element. Nevertheless, according to various embodiments, the bendable arm, when deflected, can exert sufficient lift or upward force to elevate the sheet off of the frame, and keep the sheet clear of snagging edges or other projections or hazards as it travels across the stripping, blanking, or other work area. According to various embodiments, multiple deflectable lifting devices can be mounted in the bridge or other frame of the work area, creating a balanced elevation of the sheet or web across an entire span.

DETAILED DESCRIPTION

According to various embodiments of the present teachings, as illustrated inFIG. 2, a deflectable lifting device100can comprise a base102and a bendable arm104. According to various embodiments, the deflectable lifting device100can be formed of plastic, metal, wood, or other material. In some embodiments, deflectable lifting device100can comprise polyurethane, for example, polyurethane 75 D, or other plastic or resin material. In some embodiments, the deflectable lifting device100can have dimensions, for example, such as those illustrated inFIGS. 3,4,9(A), and9(B), or it can have other dimensions or shapes. The deflectable lifting device100can be formed in a unitary structure. According to various embodiments, the deflectable lifting device100can be made from separate components, parts, or materials, that are joined together, for example, using adhesives or other joining techniques or materials, to form a composite deflectable lifting device.

According to various embodiments and also illustrated inFIG. 2, the deflectable lifting device100can be mounted in a mounting slot106of a support108. Support108can be, or can include, for example, a plywood or other beam, bridge, spine, truss, joist, joint, or other support member or structure. In some embodiments, the base102of deflectable lifting device100can have a size, shape, and contour that is generally complementary to the mounting slot106. In some embodiments, the deflectable lifting device100can be mounted in mounting slot106using a snap-fit, friction fit, compression fit, or other insertion or fitting technique. According to various embodiments, deflectable lifting device100can be inserted into mounting slot106from a side position as shown, for example, manually or other insertion or fitting technique. According to various embodiments, deflectable lifting device100can be mounted from, or inserted from, the top of mounting slot106, or it can be mounted from another mounting receptacle.

According to various embodiments and as illustrated inFIG. 2, deflectable lifting device100can comprise a recess110into which bendable arm104can deflect or be depressed. In some embodiments, bendable arm104can include an arcuate portion112, which generally comprises an upwardly extended rounded protuberance or head. Arcuate portion112can present a gently curved or rounded contact surface over which the sheet of paper or other material can slide. In some embodiments, the sheet of paper or other material is thereby lifted or elevated from the surface of support108, for example, by a distance between 1.0 and 10 millimeters, or a distance of greater or lesser elevations. Deflectable lifting device100can resist deflection of bendable arm104under the weight of the sheet or web, by itself.

According to various embodiments and in orientations as illustrated inFIG. 2, when a sheet of paper or other material is conveyed from left to right (indicated by a direction arrow), the sheet or web can come into contact with deflectable lifting device100. In some embodiments, during stripping or blanking operations, the leading edge or distal tip of the bendable arm104can deflect downward under the applied force of tools or materials used in such operations, for example, a speed bar, presser bar, other tool, or foam, in the case of a female stripper implementation. According to various embodiments, bendable arm104elastically deforms or deflects downward with a spring action into recess110in response to applied tooling or other forces. Bendable arm104can be deflected to an elevated position with respect to the adjacent surface of support108. According to various embodiments, the sheet or web of paper, or other material, can be driven or pulled through a pathway, which can include a work station, using a motor or other source of power.

According to various embodiments, this clearance or elevation can permit the sheet or web of paper, or other material to be conveyed across support108or other work areas, without snagging or jamming on exposed edges, corners, joints, projections, or other potential obstructions or hazards. In some embodiments, directing the sheet or web of paper, or other material in a direction from left to right in the orientation shown can assist in preventing the sheet or web of paper, or other material from potentially snagging under the tip of the bendable arm104.

According to various embodiments, the elevation of the sheet or web of paper, or other material elevated by deflectable lifting device100, can also result in fewer scratches, gouges, streaks, tears, or other unintended manufacturing marks or imperfections being impressed on the sheet or web that can arise due to contact with screws, nails, fasteners, splinters, imperfections in frames, work surfaces, or other contact or friction. The contact of the sheet or web against the head of the comparatively small arcuate portion112can result in a contact point or patch that is likewise small in area, which creates a bearing effect that reduces drag and facilitates movement of the sheet or web.

According to various embodiments, when no tooling force or other pressure is applied, the spring action of bendable arm104can return bendable arm104to its normal, unbiased, upwardly extended position. The manufacture of deflectable lifting device100from polyurethane 75 D, durable plastic, or other polymeric material, for example, a polyolefin or polytetrafluoroethylene, can result in the expected service life of deflectable lifting device100to attain on the order of a million or more mechanical deflections, flexes, bends or other movements or deformations. This durability, in one regard, can reduce the need for maintenance and repair of deflectable lifting device100, support108, and the associated work area, work tools, and other components of the processing station or stations, for instance, when compared to a metal bridge rule or other rigid separator part.

According to various embodiments and as illustrated inFIG. 2, support108can comprise connecting notches114, which can permit multiple supports108to be connected or coupled, in a daisy-chain fashion. Support108can also be connected using connecting notches114to other supports or other members. Deflectable lifting device100, as illustrated therein, resides in a normally biased, upwardly extended position when no sheet or web of paper, or other material is in contact with bendable arm104.

According to various embodiments and as illustrated inFIG. 3, according to the present teachings in another regard, the base102of deflectable lifting device100can have one or more rib, nib, tooth, or other protrusions128which can contact the interior rim of mounting slot106, which can also create or reinforce a snap-fit, friction fit, compression fit, or other fitting or mounting arrangement. According to various embodiments and as described herein, the base102can incorporate slots or channels for the same purposes. Once deflectable lifting device100is inserted into the mounting slot106, deflectable lifting device100can remain in a relatively fixed position mounted in slot106, due to snap-in, friction fit, compression fit, adhesive, or other fitting, mounting, coupling, or attachment devices and/or techniques. In some embodiments, protrusion128can be formed as one or more projecting, tooth-like members that extend from an end wall of base102, which can resist forces tending to pull deflectable lifting device100out of slot106, in an anchoring fashion. Protrusion128can reinforce or enhance the security of the fitting in slot106or other mounting recess, because a greater force would be required to extract or dislodge deflectable lifting device100from the slot106. In some embodiments and as illustrated inFIG. 3, a protrusion128can be formed in each end wall of base102. According to various embodiments, only one protrusion128can be formed, in either or both end walls of base102, or in other locations.

According to various embodiments and as illustrated inFIG. 3, according to the present teachings in another regard, the base102of deflectable lifting device100can have formed therein one or more vertical slots126, which can extend from a bottom surface thereof. One or more vertical slots126can create a firm friction fit or compression fit in mounting slot106, and/or help to relieve flex or tension imposed on deflectable lifting device100, when under load.

According to various embodiments and as illustrated inFIG. 4, protrusion128can be, or can include a lateral or sideways bulge, which can have a width comparable to the width of base102of deflectable lifting device100, which will create a more secure fit for the deflectable lifting device100in slot106. Protrusion128can be or can include a tooth-like projection, a width-wise bulge, or both configurations.

According to various embodiments and as illustrated inFIG. 5, a retaining structure can also be formed as a set of multiple protrusions130, which can be in a saw-tooth pattern or other configuration. The set of multiple protrusions130can likewise be formed in one or both end walls of base102, or in other locations.

FIG. 6generally illustrates the mounting and placement of one or more of deflectable lifting devices100in a stripping station116that can be used to carry out stripping operations on a sheet152, such as a sheet or web of paper, plastic, or other material. As generally shown, stripping station116can comprise a stripping surface118, over which sheet152can be passed, illustratively in a right to left direction (indicated by the arrow) as shown, to be punched, cut, compressed, or otherwise contacted to remove or alter selected areas of the sheet152, leaving the overall expanse of the sheet152intact, with desired portions stripped or removed. In some embodiments, a male stripping element, for example, a blade, die, hammer, punch, or other working tool, can descend or otherwise move into contact with the sheet152to cut, punch out, or otherwise alter the sheet152. According to various embodiments, the male stripping element can align with female stripping regions, recesses, or voids, to permit stripped-out material to be removed from sheet152and deposited into the recess of the frame of stripping station116.

According to various embodiments, and as shown inFIG. 6, for example, multiple deflectable lifting device or devices100can be mounted into stripping surface118, to lift the sheet152in an even or balanced manner over desired sections of stripping surface118or other surfaces. While various embodiments, for example, illustrated inFIG. 6, are shown with the deflectable lifting device100members arranged in a regular line, grid, spacing or pattern, it will be understood that any number of deflectable lifting device100members can be mounted in stripping surface118, and in any other desired pattern or arrangement.

FIG. 7generally illustrates the mounting and placement of one or more of deflectable lifting devices100in a blanking station120that can be used to carry out a blanking process on a sheet152, for example, a sheet or web or paper or other material. According to various embodiments, blanking station120can generally comprise a set of support bridges122and blanking recesses124to capture or collect punched-out or cut-out paper or other products or materials punched out or removed from sheet152. According to various embodiments, sheet152can be conveyed illustratively in a right to left direction (indicated by the arrow) as shown, over the comparatively open areas of blanking station120. According to various embodiments, this can result in a degree of downward bow or sag in the sheet152as it is conveyed over those cavities.

According to various embodiments, one or more of deflectable lifting devices100can be mounted in one or more support bridges122of blanking stations120, to elevate sheet152being conveyed over support bridges122and blanking recesses124, to reduce or eliminate the chance that sheet152will snag, jam, tear, or otherwise become obstructed or damaged on the edges of one of the blanking recesses124, or other projections or obstructions. It can be noted that as illustrated inFIG. 7, the deflectable lifting devices100can generally be arranged in a direction parallel to the movement of the sheet152, with the lead edge or distal tip of bendable arm104deflecting downward in the direction of that movement to permit a smooth sliding action over arcuate portion112. According to various embodiments, such an orientation can prevent the sheet152from jamming under the tip of bendable arm104.

FIGS. 8(A) and 8(B)illustrate a deflectable lifting device100according to various embodiments of the present teachings, including embodiments having one or more through-holes in the base. In some embodiments and as shown inFIG. 8(A), deflectable lifting device100can incorporate an upper through-hole132and lower through-hole134. In some embodiments and as shown inFIG. 8(A), upper through-hole132can comprise a relatively short, rectangular hole, proximate to the fixed end of bendable arm104. According to various embodiments shown inFIG. 8(A), lower through-hole132can comprise a relatively level, oblong hole through an area of base102.

According to various embodiments shown inFIG. 8(B), deflectable lifting device100can incorporate an upper through-hole136and lower through-hole138. According to various embodiments shown inFIG. 8(B), upper through-hole136can comprise a relatively elongated, generally rectangular hole, proximate to the fixed end of bendable arm104. In some embodiments and as shown inFIG. 8(B), lower through-hole138can comprise a relatively inclined, oblong hole through an area of base102.

According to various embodiments, for example, as illustrated inFIGS. 8(A) and 8(B), the incorporation of through-holes can reduce the weight and amount of material used to fashion the deflectable lifting device100. Incorporation of one or more through-holes proximate to the bendable arm104, in the base102, or in other areas can also result in increased flexibility in desired areas because dividing walls between the through-holes can absorb forces and potentially flex, depending on material thickness and/or other factors. The incorporation of through-holes can relieve or reduce repetitive mechanical stresses through various portions of the deflectable lifting device100. According to various embodiments, one or more numbers of through-holes can be incorporated in the deflectable lifting device100. In some embodiments, areas of carved-out, fluted, or otherwise removed or altered material can be used instead of, or along with, through-holes and/or other features.

According to various embodiments and as illustrated inFIG. 9(A), deflectable lifting device100can incorporate a head142at the distal end of bendable arm104. According to various embodiments, head142can comprise a generally oblong or oval structure. According to various embodiments as shown, head142can include a head through-hole144. Head through-hole144can comprise a generally oblong, oval, or other shaped hole, formed through head142. As shown, both head142and head through-hole144can be configured with a longest, length-wise axis generally aligned in a vertical direction. According to various embodiments, other orientations of head142and head through-hole144can be used. Bendable arm104can be configured to rise at a relatively steeper or greater slope or angle of inclination, terminating at the top of head142and at a higher elevation, resulting in a deflectable lifting device100that is relatively compact. The incorporation of head through-hole144can reduce the weight and the amount of material used to fashion the deflectable lifting device100. Head142can be formed without a head through-hole144, or with two or more head through-holes.

According to various embodiments and as illustrated inFIG. 9(B), deflectable lifting device100can incorporate a mounting groove140, for insertion and registration with, for example, a tooth, tongue, or other projection formed in the frame of a stripping station, blanking station, or other structure or support. As illustrated inFIG. 9(B), the mounting groove140can be formed as a rectangular channel in a length-wise vertical direction in base102. According to various embodiments, other shapes, depths, and orientations of mounting groove140can be used.

According to various embodiments and as illustrated inFIG. 10, deflectable lifting device100formed with mounting groove140can be mounted into a mounting slot150of support148. According to various embodiments illustrated inFIG. 10, the mounting slot150can incorporate a mounting strip146. In some embodiments as shown, the mounting groove140of deflectable lifting device100can slidably register or mate with the mounting strip146to mount deflectable lifting device100to support148. Mounting groove140can extend through the entire thickness of support148, creating a through-hole. In various embodiments, a depth of base102of deflectable lifting device can be configured to match a depth of mounting groove140, so that the base102does not project from an underside of support148. In some embodiments, mounting groove140can be configured so as not to penetrate the entire thickness of support148. According to various embodiments, the base102or other portions of deflectable lifting device100can instead be secured to support148using adhesives, magnets, hook-and-loop attachments, or other techniques.

According to embodiments and as illustrated inFIG. 10, deflectable lifting device100can be mounted in a support148in pairs that are located in relatively close proximity. According to various embodiments, deflectable lifting device100can be mounted alone in desired areas, or more than two deflectable lifting device100can be located in relatively close proximity. WhileFIG. 10and other figures generally illustrate that two or more deflectable lifting devices100can have the same size and configuration, according to various embodiments, multiple deflectable lifting devices100can comprise different sizes, shapes, configurations, orientations, and/or different materials.

According to various embodiments and as illustrated inFIG. 11, deflectable lifting device100can be mounted in support148. As illustrated inFIG. 11, the bendable arm104of deflectable lifting device100can reside in an unbiased position as shown such that a lower end of head142lies beneath the surface of support148, and can be partially recessed in mounting slot150. Therefore, according to various embodiments as shown, the sheet or web of paper or other material traveling over deflectable lifting device100can be presented with no recess, crevice, or catch upon which to snag or jam itself in the device. According to various embodiments, it can also be made difficult or impossible for the sheet or web of paper or other material to snag or jam on deflectable lifting device100, whether that sheet or web of paper or other material is conveyed in a direction parallel to the deflectable lifting device100, or otherwise. While two deflectable lifting devices100are shown as mounted or installed inFIG. 11, according to various embodiments, a single deflectable lifting device100, or more than two deflectable lifting devices100, can be mounted in one or more areas. (A third, un-mounted deflectable lifting device100is shown inFIG. 11, merely for illustration).

According to various embodiments and as illustrated inFIG. 12, deflectable lifting device200can comprise base portion201, which can have top surface202, bottom surface204, leading edge206, and trailing edge208. In some embodiments, deflectable lifting device200can further comprise bendable arm210. In some embodiments and as illustrated inFIG. 12, bendable arm210can comprise bendable arm trailing edge214and trailing edge curved surface212, which can curve towards the trailing edge208of base portion201. According to various embodiments, bendable arm210can comprise bendable arm top surface216, which can rise above the plane defined by top surface202of base portion201. Bendable arm210can comprise bendable arm bottom surface218, which can extend below the plane defined by top surface202of base portion201.

According to various embodiments, also illustrated inFIG. 12, base portion201can comprise a notch220, which can be formed therein to assist in securing lifting device200in a corresponding slot of a retaining board.

According to various embodiments and as shown inFIG. 12, the bendable arm can be connected to a bottom portion or end of the base portion, as opposed to being connected to the top portion of the base portion as shown inFIGS. 9(A) to 11. In some embodiments, because of this, mechanical loads and flex points of bendable arm201can be redistributed, compared to other points of attachment.

In some embodiments, the lifting device can comprise a molded article which can comprise an acetal resin, for example, an acetal polyoxymethylene resin such as DELRIN®, available from E.I. DuPont de Nemours and Company, Wilmington, Del., or other resin or material can be used.

FIGS. 13 and 14illustrate a bottom and side view, respectively, of a deflectable lifting device200with illustrative dimensions shown. It will be appreciated other dimensions or sizes of deflectable lifting device200can be used.

Another embodiment of the present teachings is shown inFIGS. 15-18. A lifting device300is shown in a deflectable arm302and a body304. Arm302comprises a distal head308and is connected to body304. Body304comprises a bottom310and a slot306formed therein. Slot306is designed to accommodate a protruberance316provided in a retaining slot312of a retaining board314, for example, a retaining board as shown inFIG. 18, that comprises an inner peripheral face318of a blanking station. In some embodiments, device300can temporarily support a workpiece in a blanking station just prior to the workpiece being blanked. As is shown, arm302and head308can extend into a blanking recess of a blanking press and can be deflectable by the blanking press during a blanking operation. Such a blanking recess can comprise inner peripheral318as shown inFIG. 18.

Other embodiments will be apparent to those skilled in the art from consideration of the present specification and practice of various embodiments disclosed herein. It is intended that the present specification and examples be considered as exemplary only.