US3633903A

US3633903A - Sheet-transporting assembly

Info

Publication number: US3633903A
Application number: US1119A
Authority: US
Inventors: Joseph E Foster Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-07-10
Filing date: 1970-01-07
Publication date: 1972-01-11
Anticipated expiration: 1989-01-11
Also published as: FR1604067A; DE1774485A1; GB1234066A

Abstract

A sheet-transporting assembly including a continuous suction conveyor which operates continuously to carry previously die-cut and stripped cardboard blanks to a predetermined location whereat a vertically reciprocal grid system activated by an automatic signal operates to separate the said blanks from the conveyor and deposits the blanks upon a descending pallet elevator system.

Description

United States Patent Joseph E. Foster, Jr.

723 Lincoln Hwy., Exton, Pa. 19341 Jan. 7, 1970 Jan. 1 l, 1972 Continuation of application Ser. No. 730,073, May 17, 1968. This application Jan. 7, 1970, Ser. No. 1,119

inventor Appl. No. Filed Patented SHEET-TRANSPORTING ASSEMBLY 3 Claims, 10 Drawing Figs.

U.S. Cl 271/74, 271/88 Int. Cl B65h 29/32 Field of Search 271/74, 68,

References Cited UNITED STATES PATENTS 2,969,869 l/196l Klinger 271/74 X 3,205,999 9/1965 Thomas... 271/74 X 3,305,233 2/1967 Cody 271/74 3,477,558 11/1969 Fleischauer 271/74 X 3,490,764 1/1970 Muller et a1. 27/74 Primary Examiner-Joseph Wegbreit Altorney- Karl L. Spivak PATENTEUwmm 3.333303 SHEET 2 UF 6 JOSEPH E. FOSTER, JR.

KM/ W PATENTED m1 1 m2 3533903 SHEET 3-0F 6 INVENTOR= JOSEPH E. FOSTER,JR

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PATENTEDJAN: 1 1912 31533903 sHmuuFe FIG. 30 98 hlln mh INVENTOR= c I BY JOSEPH E.FOSTER,JR.

PMENIEU ma 1 m SHEET 6 BF 6 |NVENTOR= JOSEPH E. FOSTER,JR.

SHEET-TRANSPORTING ASSEMBLY BACKGROUND OF THE INVENTION This invention is a continuation of my copending application Ser. No. 730,073 filed May 17. 1968, and entitled Continuous Suction Conveyor Stacker."

This invention relates in general to the paper-converting industry and more particularly is directed to a sheet-transporting assembly finding utility in stacking previously die-cut and stripped cardboard stock.

The present invention is designed for use in the paper-converting industry in the cutting and creasing operations. It is present practice to employ automatic cutting and creasing machines to cut and crease paper stock from one tenthousandth to one hundred-thousandth of an inch in thickness. These machines deliver the paper stock automatically in skid loads approximately 4 to 5 feet in'height with the die-cut waste portions still attached.

There is also automatic equipment in use for stripping previously die-cut and creased cardboard blanks, but such equipment must be set up and timed to match each particular product that is fed from the diecutting machine. The instant machine improves over the prior art in that it is the only machine available that will strip all internal and external waste from die-cut blanks without setup, that can carry the finished product uniformly after it is free of waste and then stack the said blanks onto pallets continuously to obtain piles of any predetermined, desired height.

The machine is capable of handling 4,000 previously die-cut and stripped sheets per hour without requiring setup. The machine is unique in that it is not necessary to orient or time the die-cut sheets to the machine in order to remove the waste portions of the sheet and to stack them on a skid in an even pile in the order in which they were cut. Applicant is aware of no other prior art devices designed for and capable of automatically and continuously stripping the waste from die-cut cardboard stock and transporting the stripped sheets for stacking upon pallets.

Prior art cardboard stock handling machines have utilized suction conveyors to transport the sheets from one location to another. Such devices generally function as designed and are suitable for the use intended. However, in order to separate the sheet being transported from the suction conveyor, prior art machines have incorporated mechanisms either to intermittently stop the conveyor or the suction fans in order to deposit the transported sheets at the desired terminal location. The intermittent starting and stopping of the equipment necessarily limits the speed of the operation and in addition, causes increased maintenance expenditures due to mechanical wear of the moving parts. Additionally, prior art cardboard stock handling machinery required normal adjustment and considerable setup time to compensate for cardboard stock of different sizes. The additional setup time and workers time required in order to accommodate sheets of different sizes has resulted in greatly increased handling costs during normal operating periods.

SUMMARY OF THE INVENTION The instant device seeks to overcome the shortcomings of prior art machines by providing a means and method of transporting paper stock from one location to another across the machine in a continuous manner without interruption or stoppage of the operating cycle. In addition, means have been provided to automatically separate the cardboard stock from the suction conveyor while the conveyor continuously moves and to deposit the die-cut and stripped sheets upon an elevating pallet capable of continuously descending in response to automatic signals monitoring the height of the pile of blanks deposited thereon.

A unique cardboard blank separating grid system compris ing a plurality of wires passing through the suction conveyor and capable of reciprocal motion therethrough at right angles to the plane of operation of the conveyor functions to disassociate the cardboard blanks from the conveyor at a predetermined location without interruption to or interference with the continuous operation of the suction conveyor.

It is therefore an object of the instant invention to provide an improved, sheet-transporting assembly of the type set forth.

It is another object of the instant invention to provide a sheet-transporting assembly capable of stripping, transporting and stacking 4,000 previously die-cut cardboard blanks per hour.

It is another object of the invention to provide a novel sheettransporting assembly capable of transporting and stacking previously die-cut cardboard blanks in a continuous manner without intermittently stopping the suction conveyor.

It is another object of the instant invention to provide a sheet-transporting assembly incorporating grid system functioning at right angles to the direction of travel of the conveyor.

It is another object of the instant invention to provide a novel, sheet-transporting assembly incorporating a grid system comprising a series of wires passing through portions of the suction conveyor and having reciprocating motion with respect thereto.

It is another object of the instant invention to provide a novel, sheet-transporting assembly including a pallet elevator system to receive the previously die-cut and stripped cardboard blanks.

It is another object of the instant invention to provide a novel, sheet-transporting assembly including a pallet elevator system responsive to signals to automatically lower the pile so that succeeding sheets of cardboard stock can continuously be placed on top to form a pile of predetermined height for easy handling.

It is another object of the instant invention to provide a novel, sheet-transporting assembly including in one machine the operations of vibrating cardboard blanks, removing waste portions from previous die-cut operations, transporting the said die-cut and stripped sheets upon a continuous suction conveyor and depositing said sheets upon a descending pallet elevator system.

It is another object of the instant invention to provide a novel stripping and stacking machine capable of handling finished products uniformly without nicking them together.

It is another object of the instant invention to provide a novel, sheet-handling assembly that is rugged in construction, simple in design and trouble-free when in operation.

Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment thereof, taken in conjunction with the accompanying drawings wherein like references characters refer to similar parts throughout the several views and in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a right front perspective view of the device showing the stripping mechanism and suction and pressure chambers.

FIG. 2 is a rear perspective view of the assembly showing the descending pallet elevator system.

FIG. 3 is a partial cross-sectional view taken along line 33 of FIG. I looking in the direction of the arrows and showing generally the front half of the machine.

FIG. 3a is a partial cross-sectional view taken along line 3- 3 of FIG. 1, showing generally the rear half of the machine and continuing the view of FIG. 3.

FIG. 4 is a partial, cross-sectional view similar to FIG. 3a showing the grid system in lower position.

FIG. 5 is a top plan view of a perforated suction box.

FIG. 6 is a cross-sectional view taken along line 66 of FIG. 4, looking in the direction of the arrows.

FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 5, looking in the direction of the arrows.

FIG. 8 is a left front perspective view of the device.

FIG. 9 is a detail view of the perforated suction box.

DESCRIPTION OF THE PREFERRED EMBODIMENT Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of my invention selected for illustration in the drawings and are not intended to define or limit the scope of the invention.

Referring now to the drawing, it will be seen that the device consists generally of a vibrating and stripping section generally designated A wherein previously die-cut cardboard blanks 14 are fed by the cutter and creaser (not shown) toward the impactor 12 for vibrating the waste portions free from the blank as will hereinafter be more fully set forth. The stripped blank 14 then travels across the machine upon the underside of the suction conveyor system generally designated B. The suction conveyor system B integrally incorporates the vertically reciprocating grid system C which functions to precisely separate the previously stripped blanks from the suction conveyor system B and to deposit the blanks upon a pallet carried by a descending pallet elevator system herein generally designated D.

A pair of cooperating upper and lower feed rollers l6, l8, feed individual cardboard blanks 14 over the finger section 22, to receive multiple impacts imposed by the rotation of the impactor 12. The corners of the rectangular impactor l2 protrude through the finger section 22 and impart multiple impacts upon the underside of the cardboard blanks 14 in the manner previously fully illustrated and disclosed in United States Pat. No. 3,270,929. Preferably, the impactor 12 rotates at 3000 r.p.m. for optimum results. As illustrated, the impactor is constructed of square cross-sectional configuration and thereby provides four striking surfaces each revolution. It is therefore seen that the impactor is capable of striking the cardboard blanks 14 at a rate of 12,000 times per minute when rotating at optimum speed. In accordance with the teachings of US. Pat. No. 3,270,929, it can be appreciated that the forward edge of the blank 14 vibrates freely upon contact with the impactor 12 after it feeds through the

intake rollers

16, 18.

Similarly, the trailing edge of the blank 14 vibrates freely due to the contacts of the impactor 12 when the forward edge of the blank 14 feeds into the nip of the upper and lower discharge rollers 24, 26. The combination of the vibrating action of the sheet itself and the force of the multiple rotary blows of the impactor cooperate to shake the die-cut scrap sections 36 free from the usable portions of the blank sheet 14.

An upper blower 28 powered by an electrical motor 30 pressurizes the chamber 32 which is sized to substantially over-lie the area defined by the

intake rollers

16, 18 and the discharge rollers 24, 26. In this manner, air from the blower 28 impinges upon the upper surface of the blank 14 to force the lower surface of the blank 14 into position against the finger section 22 to continuously receive impacts from the rotary impactor 12. The pressure of the air from the blower 28 further serves to assure maximum contact between the impactor and the blank 14 as the blank 14 feeds through the vibrating and stripping section A. The lower blower 34 receives its suction through the waste removal chamber 38 and serves as a vacuum-cleaning operation in cooperation with the impactor 12. The waste particles 36, which are vibrated free by the operation of the impactor l2 and the vibrating action of the leading and trailing edges of the blanks 14 as they pass respectively between the rollers l6, 18, 24, 26 are pulled by the vacuum of the lower blower 34 through the waste removal chamber 38 for ultimate disposal at the fan discharge 40. A motor 42 powers the lower blower 34 through a conventional drive 44 in a well-known manner.

Following removal of the waste particles 36, the blank 14 travels rearwardly out of the vibrating and stripping section Av under impetus of the upper and lower discharge rollers 24, 26 through the lower roller 46 and upper segmented skate roller 48 which cooperate to drive the stripped blanks onto the suction conveyor system B.

The suction conveyor rolls 52, 54 are rotatively carried respectively on the

shafts

56, 58 which are journaled through the right and left machine supports 64, 66 and rotate affixed sprockets for chain drive purposes. The driving motor 60 functions to rotate the suction conveyor 50 which is trained about the roll-affixed sprockets through a chain drive 70. The chain drive 70 operatively connects to a direct-connected driving gear 62 and to a driven gear 68 which may be pinned or otherwise affixed to the end of the leading suction roll shaft 56 in the usual manner.

Referring now to FIGS. 5, 6 and 7, the suction conveyor 50 comprises an endless chain rotating about the leading and trailing suction rolls 52. 54 and includes a plurality of horizontally juxtaposed, elongated, perforated, transverse, suction boxes 72 which are operatively affixed to the supporting conveyor links 74 as required for longitudinal and rotative motion with respect to the stripping machine 10. Each suction box 72 comprises a plurality of transverse segments 76 joined together through the longitudinal, arched junctions 78 which rise above the floor of each segment to provide a plurality of spaced, longitudinal, grid-receiving slots 80. The floor 82 of each segment 76 is drilled or otherwise provided with a plurality of openings 84 as hereinafter will be more fully set forth. Each suction box 72 is substantially channel-shaped in cross section having the openings 84 drilled through the web section between the right and left

flanges

86, 88. Each segment 76 is preferably provided with five suction openings 84 of elevensixteenths inch diameter each and arranged in a cross pattern for optimum operating efficiency.

Fans 96 overly the medial portion of the suction conveyor 50 and are powered through a belt drive 92 by the electrical motor 30 in well-known manner. The fans 96 draw their suction directly through the multiple openings 84 provided in the suction boxes 72 and thus create sufficient suction pressure to attract and carry the cardboard blanks 14. The fans discharge directly upwardly through a discharge plenum 98 through operatively affixed suction control louvers 100. The louvers 100 may be manually operated as a conventional volume damper in the usual manner to precisely control the air volume and thus the suction pressure imposed at the suction openings 84. In this manner, the suction pressure available at the conveyor 50 may be readily adjusted as required to pick up and carry previously die-cut and stripped cardboard blanks 14 across the conveyor for deposit upon the deelevating pallet system D" as hereinafter more fully discussed.

Referring now to FIG. 3a a reciprocating grid system C" comprising a plurality of spaced, horizontally disposed, longitudinal, separating wires 104 may be observed. Each wire 104 longitudinally stretches between the front and rear grid bars 106, 108, which are reciprocal between an upper position and a lower position 112 (FIG. 4) in response to automatic sensing devices as will hereinafter be more fully explained. Each grid wire 104 respectively lies within the aligned suction box slots 80 and permits longitudinal motion of the suction boxes with respect therewith as the conveyor 50 rotates about the rolls S2, 54. Individual tumbuckles 114 function to permit individual tension adjustment of the respective grid wires 104.

The front and rear grid bars 106, 108, vertically reciprocate a distance of approximately 2 inches in response to operation of the air cylinder 120. The vertical reciprocal distance must be sufficient to positively separate the cardboard blanks 14 from the suction attraction of the blowers 96. A sensing device 122, which may be an electric eye, a microlimit or suitable combination of the two, precisely senses the leading edge of the blank 14 when the blank is transported to a position over the deelevating pallet system to activate the air cylinder 120. The air cylinder functions through the crosshead 124 and quickly lowers the entire grid system and the affixed front and rear grill bars 106, 108 approximately 2 inches, thereby forcing the blank 14 downwardly away from the bottom of the suction boxes 72 to release the blanks from the attraction of the suction forces impressed at the openings 84 by the blowers 96.

The right and left sleeve bearings 126. 128, 130, 132 journal the

vertical grid shafts

134, 136 and facilitate rapid, aligned, reciprocal movement of the grid system C.

The deelevating pallet system D receives the cardboard blanks 14 which are transported by the conveyor system B and released therefrom by the separating action of the grid system C. A horizontal platform 138 provides the base of the deelevating pallet system D" and functions to removably receive pallets (not shown) in well-known manner upon which the previously die-cut, stripped and transported cardboard blanks 14 are automatically piled as herein set forth. The individual pallets may be removed from the platform 138 after being loaded by using conventional forklift trucks in the usual manner. The platform 138 securely rests upon the transverse supports, 140, 142 which in turn are end carried by the elevating

chains

144, 146, 148, 150. Right and left

clutch brakes

152, 154 turn the respective elevating shafts 156, 158 through gear drives 160, 162 in the usual manner to rotate the respective chain gears 164, 166, 168, 170, which are affixed respectively upon the shafts 156, 158.

The

chains

144, 146, 148, 150 rotatively engage the teeth of the

gears

164, 166, 168, 170 to thus raise or lower the platform 138 in response to the operation of the

clutch brakes

152, 154. The

counterweights

172, 174, 176, 178 respectively end connect to the

chains

144, 146, 148, 150 and serve to equalize the weight of chains about the

gears

164, 166, 168, 170 in the usual manner to compensate for movement of the chains.

A second sensing device 180, which may be an electric eye circuit, determines the height of the pile 182 of cardboard blanks 14 deposited upon the platform 138 and functions to lower the platform 138 by activating the

clutch brakes

152, 154 in response to the buildup of the pile 182 by successive deposits of transported blanks. In this manner, the tope 184 of the pile may be maintained at a constant vertical distance from the bottom of the suction conveyor 50 at all times in response to the operation of the sensing device 180. When the pile becomes 4 or 5 feet in height as predetermined by the operator, the entire pallet (not shown) with the pile 184 of stripped cardboard blanks 14 may be removed from the platform 138 by utilizing the usual forklift type of equipment and a new pallet can then be inserted in lieu thereof to receive further deposits of stripped and transported blanks.

lclaim:

1. In a sheet-transporting assembly for individually carrying sheets of material, the combination of A. a continuous suction conveyor carrying the said sheets by fan suction forces,

1. said suction conveyor including a plurality of parallel, transverse suction boxes arranged in an endless loop, each said suction box being provided with a plurality of suction openings,

2. each suction box being provided at the bottom thereof with a plurality of spaced, grid wire receiving slots,

a. said slots extending in the direction of sheet travel and being longitudinally aligned to define continuous grid wire receiving areas;

B. sensing means detecting the leading edge of each sheet at a precise location along the suction conveyor to activate the grid means to separate the sheet from the suction conveyor; and

C. grid means responsive to detection signals from the sensing means,

1. said grid means including an operator connected to front and rear bars, said bars reciprocating between an upper position and a lower position in response to function of the operator,

2. said grid means further including a plurality of longitudinally extending, spaced, parallel wires, said wires respectively connecting between the front and rear bars,

a. said wires lying within the grid wire receiving slots when the front and rear bars are in the upper position and said wires positioning below the suction boxes when the front and rear bars reciprocate to the lower position to thereby push the sheets away from the suction boxes and out of the range of attraction of the fan suction forces.

2. The invention of claim 1 wherein the said slots are of a depth greater than the height of the wires and wherein the wires position completely within the wire-receiving areas when the bars reciprocate to the upper position.

3. The invention of claim 2 wherein the said operator includes an air-activated cylinder and a crosshead responsive to the cylinder and respectively connected to the front and rear bars. v

Claims

1. In a sheet-transporting assembly for individually carrying sheets of material, the combination of A. a continuous suction conveyor carrying the said sheets by fan suction forces, 1. said suction conveyor including a plurality of parallel, transverse suction boxes arranged in an endless loop, each said suction box being provided with a plurality of suction openings, 2. each suction box being provided at the bottom thereof with a plurality of spaced, grid wire receiving slots, a. said slots extending in the direction of sheet travel and being longitudinally aligned to define continuous grid wire receiving areas; B. sensing means detecting the leading edge of each sheet at a precise location along the suction conveyor to activate the grid means to separate the sheet from the suction conveyor; and C. grid means responsive to detection signals from the sensing means, 1. said grid means including an operator connected to front and rear bars, said bars reciprocating between an upper position and a lower position in response to function of the operator, 2. said grid means further including a plurality of longitudinally extending, spaced, parallel wires, said wires respectively connecting between the front and rear bars, a. said wires lying within the grid wire receiving slots when the front and rear bars are in the upper position and said wires positioning below the suction boxes when the front and rear bars reciprocate to the lower position to thereby push the sheets away from the suction boxes and out of the range of attraction of the fan suction forces.

2. each suction box being provided at the bottom thereof with a plurality of spaced, grid wire receiving slots, a. said slots extending in the direction of sheet travel and being longitudinally aligned to define continuous grid wire receiving areas; B. sensing means detecting the leading edge of each sheet at a precise location along the suction conveyor to activate the grid means to separate the sheet from the suction conveyor; and C. grid means responsive to detection signals from the sensing means,

2. said grid means further including a plurality of longitudinally extending, spaced, parallel wires, said wires respectively connecting between the front and rear bars, a. said wires lying within the grid wire receiving slots when the front and rear bars are in the upper position and said wires positioning below the suction boxes when the front and rear bars reciprocate to the lower position to thereby push the sheets away from the suction boxes and out of the range of attraction of the fan suction forces.

3. The invention of claim 2 wherein the said operator includes an air-activated cylinder and a crosshead responsive to the cylinder and respectively connected to the front and rear bars.