US3437334A - Flatwork folder and method - Google Patents

Description

\ April 8, 1969 J. L. MALDONADO FLA'rwoax FOLDER AND METHOD Filed March 23, 1965 cfs Sheet mwnwb Saw a mlmkumns. 3

INVENTOR Jou/# L. Mmmm/4pc 4 Nwul April-8,1969 D J.L.MALDoNADo 3,437,334

FLA-TWORK FOLDER AND METHOD Filed March 25A. 1536s D INVENTOR Jui/H Muna/wpa BYl irroefvi/ United States Patent O 3,437,334 FLATWORK FOLDER AND METHOD Joseph L. Maldonado, `54 Cordova St., San Francisco, Calif. 94112 Filed Mar. 23, 1965, Ser. No. 442,065 Int. Cl. B65h 45 04, 45 00 U.S. Cl. 270-69 5 Claims ABSTRACT OF THE DISCLOSURE Apparatus and method for eliminating static electrical charges which interfere with folding of linen flatwork pieces in automatic folding machines. A charge neutralizing unit is positioned in the folding machine at a specific location beyond the point at which -a -irst transverse fold is formed in each flatwork piece but in advance of the point at which a first cross fold is thereafter formed in such piece. Each atwork piece is twice subjected to the effects of the neutralizing unit as it passes such location to insure effective electrical charge neutralization.

This invention relates generally to an apparatus and a method for folding flatwork, such as laundered and ironed linens. More particularly, this invention relates to Ian effective apparatus and method for folding pieces of flatwork which have been exposed to a source of electrical charges which would interfere with proper folding of the fiatwork if not counteracted. That is, specifically this invention involves neutralizing static or other electric-al charges which normally are picked up by the flatwork during an ironing and folding operation. To this end, an electrical charge neutralizing unit is incorporated into the folding apparatus at -a particular predetermined location in the path of travel of atwork pieces to :be folded which neutralizes electrical charges induced into such pieces from electrical sources employed in the apparatus, such as photo-electric sensing and timing devices, or from frictional sources encountered during such travel.

Machinery is presently available in the laundry industry which is designed to automatically form primary (transverse) folds and ycross folds in laundered and ironed linen fiatwork pieces, such as :bedsheets, tablecloths, and like large pieces. Because of the size of such flatwork pieces, manual handling thereof is both tedious -and timeconsuming, and therefore expensive. Also, freshly ironed pieces ready for folding are very hot, and therefore dicult to handle manually. As a result, automatic machinery for effectively folding ilatwork Without manual handling is in great demand.

While various types of folding machines have been developed heretofore, one of the more recent developments is a machine which employs photo-electrical devices for sensing the presence of successive pieces to be folded, measuring the length of a given piece, and activating pneumatic folding mechanism in accordance with the dimensions of a given piece ready for folding. However, it has been found that atwork pieces being folded in such a machine have picked up substantial electrical charges during their travels through an associated ironer and through the folding machine. Frequently such charges render the folding operation ineffective, result in jamming of the machinery conveyors, Iand produce other problems necessitating machine stoppage and maintenance activity. While attempts to overcome such problems have been made, the results have been less than satisfactory.

This invention relates specifically to the simple yet effective improvement of such a known folding machine which employs photo-electric devices so that electrical charges induced into or picked up by llatwork pieces being folded are effectively neutralized. As a result, operation ICC of the folding machine improved as taught herein on a continuous basis may be effected Without encountering the frequent work stoppages heretofore encountered.

In this regard, the problem of static electrical charges being picked up by atwork pieces being folded will vary, depending upon the atmospheric conditions in whichthe folding machine is located. For example, the problem of induction of electrical charges into atwork pieces being folded is extreme in dry hot air, while the problem is somewhat less prevalent in moist cool air. However, because of the nature of the pieces being treated and the end results sought, namely dry ironed pieces, the humidity of the atmosphere within the folding machine cannot appreciably be increased or its temperature appreciably reduced in an attempt to counteract electrical charges. Also, because of the high temperatures generated within the ironer attached to the folder, usually in excess of 300 F., great heat is conveyed on the pieces to be folded directly into the folder from the ironer. That heat compounds the problem further, as does the heat of friction created by the conveyor belts and rollers used in the ironer and folder. Thus, effective neutralization of induced static or other electrical charges encountered must be accomplished directly in conjunction with the folding machine and without resorting to humidity and temperature controls. Such neutralization is effected by this invention.

From the foregoing, it should be understood that objects of this invention include: the provision of an improved ilatwork folding apparatus; the provision of a method of neutralizing electrical charges to which flatwork pieces are exposed during mechanical folding; the provision in a atwork folding machine of a neutralizing unit at a location therein in which such unit is fully effective to neutralize electrical charges picked up by ilatwork pieces being folded; the provision, in combination, of a folding machine having electrical devices for sensing, timing and initiating folding operations, and an electrical charge neutralizing unit positioned therein; and the provision, in an apparatus for performing primary and cross fold operations on successive flatwork pieces, of an electrical charge neutralizing unit which is operatively positioned generally between primary and cross fold stations in the path of ltravel of pieces las they are being folded.

By way of further introduction, the machine as improved by this invention receives successi-ve laundered and ironed pieces of dry linen flatwork directly from an ironer positioned in conjunction therewith. Each piece is moved by conveying means through a primary folder section of the machine in which at least one and preferably two primary folds are made therein in a direction transverse to the general path of travel of the piece through the machine. The folds are produced by pneumatic means to be described.

After the primary folds are accomplished, each successive piece is moved by the conveying means to and through a cross folder section of the machine in which the direction of travel of the primary folded piece is altered to extend generally normal to its initial direction of travel. In the cross folder section at least one and preferably two cross folds are produced, by pneumatic means, in each successive piece in a direction transverse to the primary folds previously formed therein. Following the cross folding operation, each successive piece is discharged by the conveyor means to a discharge station from which it is removed manually or by other suitable means.

The machine includes devices which photo-electrically sense the presence of pieces to be folded which initiate operation of measuring and folding devices so that the primary and cross folding operations on a continuously moving series of diatwork pieces is effected automatically and sequentially. It is the photo-electric sensing devices and high frictional contact of the pieces to be folded with the machine conveyors, coupled with the hot dry atmosphere within the folding machine, which are believed responsible for the existence of substantial electrical charges encountered by the pieces in and about the machi-ne dur-ing their travel therethrough. The intensity of such charges is evident from the fact that they frequently are visible to the eye as sparks or flashes as they are neutralized.

As will be described later, the exemplary machine disclosed herein is of a t-ype capable of operating as a single lane machine in which a single series of pieces are successively handled, or as a 4double lane machine in which two side-by-side series of successive pieces are simultaneously handled.

In the following detailed description, reference is directed to the accompanying drawings in which:

FIG. 1 is a generally schematic side elevational view of the improved folding machine of this invention.

FIG. 2 is a vertical sectional view of the machine taken generally in the plane of line Z--Z of FIG. l.

FIG. 3 is a generally schematic plan view illustrating the path of travel and folding sequence of a flatwor-k piece through the machine when the same is operated in single lane fashion.

FIG. 4 is a generally schematic plan view illustrating the paths of travel and folding sequences of side-by-side fiatwork pieces through the machine when the same is operated in double lane fashion.

FIG. 5 `is a generally diagrammatic view showing the location of photo-electric sensing devices employed in the machine.

FIGS. 6, 7 and 8 are partial side elevational views of the machine illustrating the formation of primary folds in liatwork pieces and showing the locational relationship of the improved electrical charge neutralizing unit of this invention to pieces being folded.

FIG. 9 is a generally vertical sectional view through the `improved neutralizing unit of this invention.

FIG. 10 is a generally front elevation of the improved neutralizing unit taken in the plane of line 10-10y of FIG. 9.

Static electrical charge neutralizing units have been known heretofore and such units have been incorporated in machines of the general type disclosed herein. One such unit is described in Simons Patent No. 2,163,294 dated June 20, 1939. However, use of units as disclosed in that patent has been limited to overhead locations in such machines above the path of travel of tlatwork pieces being folded. In those locations the units have been ineffective to perform their intended charge neutralizing function` That is, folding machines heretofore employing such a known neutralizing unit therein have still encountered substantial problems due to electrical charges picked -up by the flatwork pieces which require numerous machine stoppages to clear the machine. Also, folded pieces frequently do not satisfy quality standards so that reironing and refolding thereof is necessitated.

With the neutralizing unit of improved construction employed in this invention, and with its location in the folding machine at a specific location beneath and closely adjacent the path of pieces being folded, effective folding of successive articles is insured, without the problems of machine stoppage or re-ironng and refolding previously encountered.

AIn this regard, heretofore the neutralizing unit has been mounted generally overhead and spaced above the path of travel of dlatwork pieces to be folded and closely adjacent the entering end of the primary folder section of the machine. In the improved machine, the improved neutralizing unit is mounted generally beneath the machine below the path of travel of pieces to be folded so that the pieces pass in close proximity to the unit. The unit is mounted at a location so that it acts upon each atwork piece after .4 at least one primary fold has been for-med in each iiatwork piece and before each piece is transferred to the cross fold section. Because of the particular location of the improved unit in the machine, each iiatwork piece is subjected to its neutralizing effect twice during the primary folding operation, rather than only once as with prior constructions.

The exact reasons why the neutralizing unit of the improved machine as disclosed herein is effective, whereas prior units as known and employed in prior machines have been generally ineffective, is not definitely known. However, inclusion of the improved neutralizing unit at the specific location described has been found effective even during operation of the machine under atmospheric conditions generally conducive to the formation of high electrical charges. While the aforementioned patent broadly discloses the use of a neutralizing unit in conjunction with a folding machine, and While such a known unit has been employed heretofore in such a machine, the effective and consistent results obtained by the apparatus and method of this invention have not been achieved heretofore.

This invention is employed in conjunction with a photoelectrically actuated, pneumatic folding machine commercially available and produced by American Laundry Machine Industries of Cincinnati, Ohio. Such a folding machine is identified by American Laundry as its Hypro Cross-Fold Folder which is capable of single lane or double lane operation. It is such a machine that is generally schematically illustrated in the attached drawings. Such a machine generally is used in conjunction with a Hypro Flatwork Ironer attached in line therewith which is produced by the same company. In such an installation, wet laundered llatwork pieces are fed into the ironer in which they are ironed and dried and from Which they pass in at unfolded condition directly and in succession into the folding machine disclosed herein. Because of the substantial heat produced in the ironer, dry ironed pieces are discharged in very hot condition and Iaccordingly carry much heat into the folding machine, thereby compounding the electrical charge problem therein as noted previously. Details of the ironer are well known and form no part of this invention and have not been illustrated in the attached drawings. Also, known features of the folding machine have been shown only generally schematically 4and only to an extent necessary to disclose the operational features thereof.

As noted previously the machine disclosed herein is capable of single lane operation, in which very large atwork pieces may be accommodated, or double lane operation, in which smaller atwork pieces may be accommodated in two lines simultaneously. Before describing details of the machine, the folding sequence for single lane and double lane operation will be described.

Referring to FIG. 3, in single lane operation each successive flatwork piece P is inserted into the machine generally symmetrically with respect to the longitudinal center line of the machine and i-s received therein fiat and wrinkle free from the ironer. The fold lines produced at successive folding stations are shown in dot-dash lines in FIG. 3. In the primary folder section, a first primary fold is made generally centrally of the piece along a line transverse to its direc-tion of travel, thereby folding the piece into two generally equal halves. Thereafter, a second primary fold is made generally centrally of the two-ply folded piece along a line transverse to the direction of travel thereby folding the piece into quarters. Following the formation of the first and second primary folds, the four-ply piece is transferred to the cross folder section of the machine in which its direction of travel is altered to extend generally at right angles to the longitudinal center line of the machine. In the cross folder section rst and second cross folds are successively formed in the piece generally transverse to its direction of travel through the cross folder section. The first cross fold converts the piece into an eight-ply folded piece and the second cross fold converts the piece into a sixteen-ply folded piece, in which condition it is discharged from the machine to a discharge table for sorting and other handling.

In double lane, operation, shown in FIG. 4, two series of side-by-side pieces P to be folded may be handled simultaneously. The folding sequence for the pieces in each series is essentially the same as with the single lane operation just described. However, with the double lane operation each of the pieces to be folded in each series is positioned on opposite sides of the longitudinal center line of the machine. For double lane operation provision is made in the cross folder section to stagger the folding positions for the first cross fold of the right and left hand series so that two side-by-side articles may be cross folded simultaneously without interfering with each other. Thus the pieces in the left hand lane have their first cross fold made at a location spaced farther from the primary fold section than the pieces in the right .hand lane.

FIG. 1 is a generally schematic side elevational view of the subject folding apparatus with one side framework panel thereof removed to illustrate internal details of construction thereof. The machine shown is generally designated 1 into which fiatwork pieces to be folded are fed in succession from the ironer (not shown). As noted py the legends on FIG. l, the machine is divided into two principal sections in which the primary and cross folds are formed.

Successive pieces P from the ironer are deposited in the conveyor means of the machine, which includes a plurality of operatively interconnected conveyors. The first conveyor, which receives pieces from the ironer, is generally designated 2 and is defined by a series of narrow laterally spaced belts 3 revolving about spaced rollers 4 and 6, at least one of which is driven, mounted between opposite framework panels of the machine. Belts 3 pass over a fiat table 7 beneath a photo-electric sensing device generally designated 8.

In a machine capable of double lane operation, the sensing device 8 comprises two laterally spaced photoelectric eyes of known construction designated E1 and E2 as seen from the diagrammatic showing of FIG. 5. Each of such eyes is positioned above one of the right or left hand lanes of the machine. Thus a large piece to be folded in single lane operation will pass beneath each of eyes E1 and E2, while in double lane operation each piece in each lane will pass beneath only one eye or the other. It should be understood that suitable controls (not shown) for single or double lane operation may be actuated by the machine operator as required.

A second conveyor, generally designated 10, receives pieces P from one end of first conveyor 2. Conveyor 10 includes a series of narrow laterally spaced belts 11 which pass over'a series of rollers 12, 13, 14, 16 and 17, at least one of which preferably is driven. Belts 11 carry each piece to be folded to a third conveyor, generally designated 20, defined by a series of laterally spaced belts 21 which pass over a series of rollers 22, 23 and 24, at least one of which preferably is driven.

The conveyor means of the primary folder section of the machine further includes a fourth short conveyor, generally designated 25, defined by a series of laterally spaced 1belts 26 which pass over two spaced rollers 27 and 28, one of which preferably is driven. Finally, a fifth conveyor, generally designated 30, is defined by a series of laterally spaced belts 31 which pass over spaced rollers 32 and 33, one of which preferably is driven. It is this last mentioned conveyor which, in conjunction with conveyor 10, transfers the primary folded pieces into the cross folder section of the machine.

While the drive mechanism for the various rollers has not been illustrated in the drawings, it should Ibe understood that the driven rollers of each conveyor may be driven from any suitable power source. In an actual operation, such driven rollers receive their power from the ironer to which the folding machine is connected. It should be apparent that the respective conveyors are driven in timed relationship with each other so that a piece may be transferred from one to the other without bunching or wrinkling. The direction of movement of the various conveyor belts is shown by the arrows appearing in FIG. 1.

Still referring to FIG. l, means for effecting first and second primary folds in each successive piece to be folded are located in conjunction with the respective conveyors. In the type of machine illustrated, such folding devices comprise pneumatic nozzle assemblies 36 and 37 located to form first and second primary folds, respectively, in each piece carried therepast by the conveyors. While the pneumatic nozzle assemblies have not been illustrated in detail, it should be understood that the nozzles are of elongated construction which extend transversely of the machine for substantially its full width. Each is designed to direct a jet of high pressure air against a piece located adjacent thereto when the nozzle assembly is actuated in response to the photoelectric sensing devices.

In a machine of the type illustrated which is capable of both single lane and double lane operation, the respective nozzle assemblies are divided into two lateral segments each of which is capable of functioning independently of the other, or in conjunction with the other, depending upon whether the machine is set for single or double lane operation. For single lane operation, both segments of each nozzle assembly are actuated simultaneously to form a fold crease the full width of the piece being folded. -For double lane operation, the separate segments of each nozzle assembly operate separately from the other to form a fold crease in pieces traveling in each of the right and left hand lanes independently of the other.

Referring to FIG. 2, the respective conveyor rollers of the various conveyors in the primary folder section, and the pneumatic nozzle assemblies, extend between opposed side framework panels, generally designated 40 and 41, and are supported thereby in suitable bearing and mounting arrangements (not shown). The nozzle assemblies are operatively connected to any suitable source of high pressure air.

The path of travel through the primary folder section of an individual sheet in both single lane or double lane operation is the same, and is as follows. After passing beneath photoelectric device 8, the leading edge of piece P is inserted between belts 3 of first conveyor 2 and belts 11 of second conveyor 10. Belts 11 carry the piece to third conveyor 20 at which the leading edge of the piece is inserted between belts 21 thereof and belts 11. At this stage the leading edge of the piece, as seen in FIGS. 1 and 6, hangs freely downwardly from third conveyor 20 until pneumatic nozzle assembly 36 is actuated.

Upon :actuation of the nozzle assembly, a jet of air is directed against the piece and a crease fold is formed transversely thereof generally intermediate its leading and trailing edges. The force of the air jet forces the crease folded edge thereof between belts 11 passing around roller 17 and belts 26 passing around roller 27 of fourth conveyor 24. Note FIG. 6. Thereafter the piece is pulled with its folded edge leading between the respective belts 11 and 26 (see FIG. 7) to transform the piece progressively into twoply primary folded condition.

The two-ply piece passes over the belts 26 and hangs freely downwardly therefrom until the second pneumatic nozzle assembly 37 is actuated. At that time, a second jet of air is directed across the piece and a second crease fold is formed (FIG. 8). The folded edge is forced by the air pressure between belts 11 of second conveyor 10 and belts 31 of fifth conveyor 30 which pass around the respective rollers 1-6 and 32 thereof as seen in FIG. 8. Belts 11 and 31 thereby draw the piece therebetween to form the second primary fold therein.

It should be understood that because the conveyor belts of the respective conveyors are relatively narrow and are positioned in laterally spaced relationship to each other on the rollers, the air jets produced when the nozzle assemblies, or segments thereof, are actuated may pass between the conveyor belts against the respective pieces to form the crease folds.

Following formation of the second primary fold, each piece in folded four-ply condition is carried by the second and fifth conveyors and 30 into the cross folder section as seen in FIG. 1, in which the leading edge of a prim-ary folded piece P is just reaching the cross folder section.

Referring to FIGS. 1 and 2, extending generally the full length of the machine is a reject conveyor 45 defined by a series of laterally spaced belts 46 (see FIG. 2) which pass over a series o-f rollers 47, 48, 49, 50 and 51. The purpose of this reject conveyor is to receive rejected pieces upon which the first primary fold is not effected and for carrying the same to a reject collection bin 53 adjacent the lower end of the conveyor as seen in FIG. 1. The machine operator has a control (not illustrated) at his disposal for over-riding the control effect of the photoelectric device 8 to preclude formation of a first primary fold therein if it is desired to reject a given piece, such as one known to be poorly laundered, torn, stained or the like. The reject conveyor 45 also provides a surface for supporting the leading end of a large piece to be folded (as seen in FIGS. 1 and 6) prior to the first primary fold being formed therein. The reject conveyor may be driven continuously, or intermittently as required, from any suitable power source acting upon one of its rollers 47 or 51.

In prior known machines, neutralizing units of the type disclosed in the aforementioned patent have been located next to the photo-electric device 8 and closely adjacent the entering end of the primary folder section and generally above the first conveyor 2. As noted previously, positioning a neutralizing unit at that location -has not been effective to produce consistently acceptable folding results with a machine of the type illustrated schematically herein and pieces being folded frequently cling to the conveyor belts and become fouled in the same. This is believed due primarily to that fact that each piece is subjected to a neutralizing effect too soon, and before the same has been subjected to the photo-electric, frictional and heat effects in the folding machine.

By positioning the improved neutralizing unit 55 of this invention in the specific location disclosed, namely generally beneath the machine conveyors as shown in FIGS. l, 6, 7 and 8, consistently -acceptable results are obtained. The function and mode of operation of the improved unit will be described hereinafter in greater detail. However, it should be noted at this point, referring to FIGS. 7 and 8, that each piece being folded is subjected to neutralizing effects of the unit after the first primary fold is made and prior to the formation of the second primary fold. Thus, each piece is subjected to the neutralizing effects of the unit twice, namely when the two-ply, once folded piece passes downwardly past roller 28 of the fourth conveyor 24, and again when the piece is drawn upwardly after the second primary fold crease has been formed therein and the fold is completed. Thus, the piece is twice passed in close proximity to the neutralizing unit before the piece passes to the cross folder section. Also, by locating the improved neutralizing unit 55 as specifically disclosed herein, it is able to act upon a flatwork piece after the same has been subjected for some time to the electrical charges existing in and around the machine (which are created by the photo-electric sensing devices, the high frictional contact of the pieces with the conveyor belts and rollers, and the high heat carried into the machine from the adjacent ironer) but before those charges result in pieces becoming fouled in the conveyors. After the primary folds have been made, the exposed surface area of each piece is appreciably decreased, thereby making it less susceptible to picking up electrical charges thereafter during its final travel through the machine.

Each primary folded four-ply piece is received by a sixth conveyor, generally designated 57, which extends the full length of the cross folder section as seen in FIG. 1. Conveyor 57 is defined by a series of narrow laterally spaced belts 5S which pass around rollers 61 and 62 at least one of which is driven by any suitable source. As seen in FIG. 1, the upper reaches of belts 58 are supported by a fiat supporting table 59 which is defined by four longitudinal sections 63 having gaps therebetween through which pieces being cross folded may be drawn, as seen in FIG. 2. To facilitate illustration, belts 58 have been omitted from FIG. 2 but it should be understood successive tiatwork pieces are carried thereby over the sectional table 59 to the first cross fold station. In this regard, it `also should be noted that conveyor 57 is operatively divided into two lateral segments capable of operating in unison (for single lane operation) or separately (for double lane operation).

Conveyor 57 is intermittently actuated and is sequentially started and stopped to permit a first cross fold to be formed in each flatwork piece presented to the cross folder section. Intermittent operation of conveyor 57 is effected in accordance with proper positioning of a given piece beneath a given pneumatic nozzle assembly which forms the cross fold in the successive pieces as will be described.

A series of photoelectric devices are positioned above the path of travel of successive articles, whether the rnachine is employed in single lane or as a double lane operation. As seen in FIG. 1, a photo-electric device, generally designated 65, is positioned closely adjacent the entering end of the cross folder section. Referring to FIG. 5, device 65 is defined by two laterally spaced photo-electric eyes E3 and E4 respectively, one of which lies above each lane of the machine. Adjacent photo-electric device 65 is another photo-electric device, generally designated 66, which is defined by two laterally spaced electric eyes ESA and ESB as seen in FIG. 5. A third photo-electric device, designated 67, is defined by photoelectric eye E10 mounted `as seen in FIG. 5 on the opposite side of the longitudinal center line of the machine from eye ESB but closely adjacent thereto.

A fourth photo-electric device, generally designated 68,

and defined by three photo-electric eyes EGA, E6B and E9 as seen in FIG. 5, is mounted in the position seen in FIG. 2 closely adjacent the end of the cross folder section. Finally, the photo-electric sensing system is completed by a final photo-electric device, generally designated 69, which is positioned Iadjacent the discharge station of the machine. The relative location of device 69, defined by two photo-electric eyes E7 and E8, is seen in FIG. 5. Referring now to FIG. 2, the cross folding sequence will be Vdescribed with respect to a single lane operation upon a large size fiatwork piece. A four-ply piece, having two primary folds therein, is carried over table 59 by the conveyor 57 until the conveyor is stopped in accordance with a predetermined plan. When the conveyor is stopped, a first cross fold pneumatic nozzle assembly 75 is actuated to direct an air jet downwardly onto the piece to form a cross fold crease therein. Nozzle assembly 75 extends longitudinally of the machine above conveyor 57 and is generally in line with the longitudinal center line of the machine. Thus, a piece centrally located in the machine will have its first cross fold produced centrally thereof. As the air jet from nozzle assembly 75 strikes the piece, the crease fold formed thereby is urged downwardly between two elongated driven rollers 76 and 77 which extend longitudinally of the machine and draw the piece downwardly through a gap between the supporting table sections to forni the cross fold thereon.

A conveyor, generally designated 78, is defined by a 9 series of laterally spaced conveyor belts 79 which pass over spaced rollers 81 and 82. Conveyor 7.8 is positioned beneath table 59 and extends transversely thereof as seen in FIG. 2.

Each successive piece having the -first cross fold formed therein is carried by the transverse conveyor 78 onto another cross fold conveyor, generally designated 83, defined by a series of spaced belts 84 which pass around aforementioned roller 81 of conveyor 78 and another roller 86 located beneath the discharge station. Belts 84 also pass over a supporting table 87. Conveyors .'78 and 83 are intermittently driven and are defined by two segments which are separately operable or operable in unison so that the machine is capable of double line or single line operation.

When a piece having its -first cross fold is properly positioned, a second cross fold nozzle assembly 89 is actuated to direct an air jet upwardly against the piece to formI a second cross fold crease therein and to -urge the crease fold upwardly between two driven rollers 91 and 92 which form the second cross fold in the piece and deposit the piece on a final discharge conveyor, generally designated 93, defined by spaced belts 94 which pass over rollers 96 and 97.

The thus folded sixteen-ply piece having two primary folds and two cross folds is discharged laterally from the 4machine onto a discharge table 100 supported by the side frame member 40 of the machine. At that location, each successive piece is normally manually inspected and sorted into piles of folded pieces of similar size.

Referring again to FIG. 2, it should be noted that on either side of aforementioned cross fold nozzle assembly 75 are two other cross fold nozzle assemblies 102 and 103 which are positioned above the left and right hand lanes of the machine to form first cross fol-ds in successive pieces when the machine is conditioned for double lane operation.

Referring to FIG. 4, it will be apparent from the location of the folded pieces being cross folded that first cross fold stations are offset longitudinally of the machine relative to each other so that the respective pieces in the respective lanes of the machine will not interfere with each other as the same are cross folded and transferred from table 59 onto conveyor 78 and moved thereby to the second cross folding station.

When the machine is employed in double lane operation, nozzle assemblies 102 and 103 are separately actuated and nozzle assembly 75 is not employed. As with nozzle assembly 75, each of the nozzle assemblies 102 and 103 have a pair of elongated driven rollers, designated 104 and 106, provided therebeneath (FIG. 2) between which folded pieces may be drawn and deposited on the cross fold conveyor 78 during double lane operation. Nozzle assembly 89 at the second cross fold station is defined by two discrete segments which may be actuated simultaneously (during single lane operation) or separately (during double lane operation).

A full sequence of operation of the machine in both the single lane and double lane operation will now `be described taking reference to the various control functions regulated by the photo-electric eye heads described previously. -In this connection, it should be understood that each of the photo-electric eyes is electrically connected by electrical relays to electronic measuring timers and solenoids which regulate actuation of the respective pneumatic nozzle assemblies as required by the length of a given piece to be folded. These auxiliary measuring and timing components are mounted in a housing 110; on the side frame member 41 as seen in FIG. 2. The mode of operation of the photo-electrically actuated control devices and their constructions form no part of this invention. Therefore, details of such operation are not included herein with only the results accomplished thereby being set out.

In single lane operation, as the leading edge of an ironed piece intercepts the light beams emitted by both photo-electric eyes E1 and E2 a measuring period is initiated to determine the length of the piece being folded. The measuring period continues until the trailing edge of the piece clears both eyes E1 and E2. If the piece is of the maximum length (generally l inches) which the machine can handle, both segments of the first primary fold nozzle assembly 36 are actuated simultaneously as soon as lboth eyes E1 and E2 are cleared. If the piece is less than maximum length, a time delay will occur, controlled by a suitable timer. In either case, the first primary fold pneumatic nozzle is actuated when the center of the piece being folded is directly opposite the nozzle 36. The aforementioned timer also automatically activates both segments simultaneously of the second primary fold nozzle assembly 37 when the two-ply folded piece is positioned centrally of such nozzle.

In this regard, only a short air blast is required, of about one-tenth second duration, to form the primary folds and cross folds. The air blast is continued only long enough to insure gripping of the folded edge of the piece by the conveyor belts or rollers adjacent to the nozzle assemblies in the primary folder section and the cross folder section.

Following formation of both cross folds, each successive piece is carried into the cross folder section. Nothing occurs when its leading edge intercepts photoelectric eyes E3, E4 and ESB (eye ESA is employed in double lane operation). However, when the trailing edge of the piece clears both eyes E3 and E4, both segments of conveyor 57 are stopped and first cross fold nozzle assembly 75 is actuated for the period required toform a first cross fold in the piece. Conveyor 57 is maintained stopped until the first cross folded piece moves laterally on conveyor 78 and clears photoelectric eye ESB, at which time conveyor 57 is reactivated to bring another piece into the cross folder section.

As mentioned previously, if the piece has been properly positioned relative to the center line of the folding machine as it is introduced into the primary folder section, the first cross fold is formed intermediate opposite ends of the primary folded pieces. As the first cross folded piece moves from the first cross fold station toward the second cross fold station, it passes beneath photoelectric eye E10 which activates a measuring timer to determine the length of the piece being cross folded. As the trailing edge of the piece clears eye E10, the cross fold measuring period is completed and both segments of the second cross -fold pneumatic nozzle assembly 89 are activated simultaneously when the piece is located centrally thereof so that the second cross fold crease is formed therein.

The photo-electric eyes E6A and B6B (eye E9 is employed in double lane operation) control the rejection of primary folded pieces which have been improperly folded. That is, if a primary folded piece has been misfolded so that it is extra long in the primary folded condition so that its leading edge passes beneath eyes E6A and B6B before its trailing edge clears eyes E3 and E4, movement of conveyor 57 will not be interrupted and the improperly folded piece will be carried by conveyor 57 into a discharge reject bin 111 located at the end of the machine as seen in FIG. l. Similarly, if a piece has been introduced crooked into the primary folder section so that it reaches the cross folder section in similarly crooked position, the piece will be rejected. For example, if eye ESB is cleared before eye E3, or eye E4, movement of conveyor 57 will continue and the crooked piece will be deposited in reject bin 111.

In this general regard, although not shown herein, the operator of the machine also has a control which permits pieces to be rejected prior to formation of the first primary fold if visual examination indicates that such is necessary.

In double lane operation as noted previously, the right and left hand lanes of the machine are capable of independent but simultaneous operation to double the capacity of the machine when smaller pieces are being handled. In such an operation, measuring and primary folding in the left lane is controlled by photoelectric eye E1. After the trailing edge of the piece clears eye E1 the left segments of the first and second primary fold nozzle assemblies 36 and 37 are activated in the manner described previously for single lane operation. Also, as with single lane operation, in the cross fold section, nothing happens when the leading edge of a primary folded piece passses beneath photo-electric eyes E3 and ESA. However, when the trailing edge of the piece clears eye E3, the left half segment of conveyor 57 is stopped and the left pneumatic nozzle assembly 103 is activated to form a first cross fold crease and place the piece on transverse conveyor 78. When eye ESA is uncovered the left half of conveyor 57 is reactivated. When the trailing edge of the laterally moving piece being cross folded also clears eye E10, the second cross fold is formed therein by actuation of one segment of the aforementioned second cross fold pneumatic nozzle assembly 89.

The left lane of the machine, as seen in FIG. 5, also has piece reject capability governed by eyes E6A and E6B so that, if oversized and improperly folded pieces are fed to the cross fold section of the machine, they will be discharged into reject bin 111.

The right lane operates similar to the left lane just described with the two primary and trst cross folding operations therein being governed by photoelectric eyes E2, E4, E7 and E8 in the manner described previously for left lane operation. In this regard, as the leading edge of a primary folded piece passes beneath photo-electric eyes E7 and E8 in the cross folding section nothing occurs. However, when the trailing edge of the piece clears eye E7 the right half of conveyor 57 is stopped and the right pneumatic nozzle assembly 102 is activated to form the first cross fold. When the trailing edge of the laterally moving piece being cross folded clears eye E8, the second cross fold is formed therein by actuation of one segment of the aforementioned second cross fold pneumatic nozzle assembly 89.

The right lane of the machine also has pieces reject capability governed by eyes E7 and E9 so that, if oversized and improperly folded pieces are fed to the cross fold section of the machine, they will be dischargedinto reject bin 111.

As noted previously, the amount of electrical charge which exists in and around the machine is substantial. Thus, each piece to be folded, whether in single or double lane operation, is exposed to high intensity electrical charges which may be induced thereinto and picked up thereby. It is such electrical charges, of either positive or negative character, which have created considerable problems, particularly when such pieces became fouled in or adhered to the numerous conveyor belts or rollers of the machine. Upon a piece becoming thus fouled it is necessary to shut down the entire machine, and the ironer in conjunction therewith, and frequently to have a maintenance man crawl into the machine to cut free the entangled piece. Thus operating time is lost and iiatwork pieces are unnecessarily damaged.

Referring now to FIGS. 2, 9 and l0, details of the improved electrical charge neutralizing unit of this invention which recties problems of the type noted by effectively rneutralizing static charges in the pieces are shown.

The electrical charge neutralizing unit generally designated 55 is connected via an electrical lead wire 120 with a power unit control box, generally designated 121, mounted on the machine side frame member 41, which preferably is grounded by any suitable means. In control box 121 and connected with unit 55 is a discharging transformer, suitably and effectively grounded, which in turn is connected to any suitable electrical source in the manner generally disclosed in said aforementioned patent, and reference is directed thereto for a general understanding of the operation thereof.

The improved neutralizing unit 55 of this invention as seen in FIG. 2 extends laterally the full width of the machine and is supported by the opposite side framework panels 40 and 41 thereof. As noted previously, the unit is specifically located beneath the path of travel of each flat work piece passing through the machine in either the single lane or double lane operation. As has been described, at such location a susbtantial portion of each piece being folded is twice subjected to the neutralizing effect of the unit as its direction of travel is reversed as seen in FIGS. 7 and 8.

The improved unit of this invention comprises an elongated metal plate 122, preferably of stainless steel, which extends substantialy the full width of the machine as seen in FIG. 2. Such width is in excess of ten feet so that the machine may accommodate pieces up to inches in width. At its upper edge plate 122 is provided with a reversely bent portion 123 which forms a channel, in the opposite ends of which are received two mounting axles 124, which in turn are received in suitable mounting brackets 126 secured in any desirable fashion to the side framework panels 40 and 41 of the machine. A series of headed pins 127 project through the upper channel portion 123 of the plate and through the respective mounting axles to secure the plate and axles integrally together.

At its lower edge the plate 122 is provided with a bent flange portion 130 which projects therefrom and extends transversely thereacross. Flange 130 terminates at its opposite ends in a pair of projecting shoulders 131 from which depend rubber bumpers 132 secured by bolts 133 or other suitable means to the shoulders 131. Bumpers 132 in turn engage and are supported by mounting brackets 134 projecting inwardly from the side framework panels 40 and 41 of the machine as best seen in FIGS. 9 and l0.

As noted in FIG. l0, the neutralizing unit is mounted generally above and in spaced relationship to the top reaches of the belts 46 of reject conveyor 45 so that rejected unfolded atwork pieces may be carried by conveyor 45 the length of the machine to reject bin 53.

Plate 122, generally intermediate its upper and lower edges, is formed with a generally U-shaped channel 136 which extends transversely thereof for its full width. A metal electrical charge eliminating bar, generally designated 137, is mounted in channel 136. Adjacent the upper portion of channel 136 is provided a generally L-shaped ange member 138 secured by welding or other fastening means to the front face of plate 122. Flange 138 defines: a projecting lip which extends the full width of plate 122. The purpose of that lip is shown in FIG. 9, namely to preclude a flatwork piece P shown in dotted lines from coming into contact with a series of discharge elements 139 which project from bar 137 at spaced locations therealong. It is elements 139 which attract and draw off the electrical charge of high intensity from each flatwork piece passing in close proximity thereto to neutralize the charge carried thereby, whether positive or negative. Because the discharge elements 139 are spaced at regular intervals along the length of the bar 137, effective neutralization of any charge induced into a flatwork piece passing thereover is insured.

Bar 137 comprises a metal shell 141 which surrounds a central rod 142 from which the aforementioned discharge elements 139 project through suitable openings in shell 141. Interposed between rod 142 and shell 141 is an insulating spacer tube 143 which extends the length of the neutralizing unit. Rod 142 is connected by lead wire 120 with the aforementioned transformer in box 121 so that charges siphoned off by the bar are transmitted to and dissipated by the grounded transformer. It is not uncommon for such charges as they pass between atwork pieces and elements 139 on bar 137 to be visible as electrical sparks.

Interposed between shell 141 and channel 136 of plate 122 are a series of spaced insulator rings 144 formed from an effective insulating material, such as a suitable phenolic resin.

As seen in FIG. 9, the improved neutralizing unit of this invention preferably is mounted generally upright in the machine with plate 122 extending at a small angle relative to the vertical. Thus a flatwork piece being neutralized may pass in close proximity to the tops of the discharge elements 139 without coming in contact therewith due to the spacing effect of the projecting lip 138. An angle of about degrees relative to the vertical, dened by the at front face of plate 122 relative to the vertical, has been found effective.

By thus providing an improved neutralizing unit of the type described, and by positioning the same at the specific location mentioned herein, a folding machine which employs numerous electrical sensing devices therein may be rendered effective to counteract electrical charges picked up by flatwork pieces being folded therein, and an effective folding method is insured. While a single improven neutralizing unit located as disclosed herein has been found elfective for the purpose described, another unit similarly constructed and similarly located in the cross folder section may be employed if particularly vexing problems are encountered with a given machine. This latter situation may be encountered, for example, if a folding machine is being operated in an arid country or state having a very dry hot climate in which sta-tic electrical charges are easily produced.

Having thus made a full disclosure of this invention and its particular applicability to a folding machine of the type disclosed herein, reference is directed to the appended claims for the scope of protection to be afforded thereto.

I claim:

1. For use in combination with a folding apparatus,

(A) a neutralizing unit for attracting an electrical charge from atwork pieces being folded in said apparatus to neutralize said electrical charges carried thereby; said unit comprising (1) an elongated generally flat plate having a channel extending transversely thereof opening to one face of said plate,

(2) means adjacent the upper edge of said plate for securing said plate in said apparatus,

(3) other means adjacent the lower edge of said plate for engagement with predetermined portions of said apparatus for supporting said plate generally upright in said apparatus but with said face at a predetermined angular relationship relative to the vertical,

(4) a lip extending transversely of said plate above said channel and projecting from said face,

(5) a charge attracting bar in said channel and extending therealong,

(6) and insulating means between said bar and said plate,

(7) said lip precluding contact of atwork pieces with said bar as such pieces pass said plate during a charge neutralizing operation.

2f. In combination, apparatus for folding fiatwork pieces, and means in conjunction with said apparatus for neutralizing electrical charges picked up by said pieces during travel through said apparatus;

(A) said apparatus comprising (l) means for conveying a series of successive flatwork pieces through said apparatus past a primary fold station and a cross fold station,

(2) means at said stations for forming primary and cross folds in each successive piece of said series,

(3) photo-electric sensing means for activating said folding means when a piece is properly oriented at a given station,

(4) said conveying means at said primary fold station carrying a portion of each successive piece in a tirst direction past a reference location and then in a reverse direction past said reference location as a primary fold is formed therein;

(B) said neutralizing means comprising an electrical lcharge neutralizing unit capable of attracting and neutralizing the electrical charges carried by said pieces,

(C) said neutralizing unit being located closely adjacent the path of travel of said series of pieces through said apparatus on said conveyor means,

(D) said neutralizing unit being positioned at said reference location generally beneath said path of travel of said pieces adjacent said primary fold station so that `a portion of each successive piece conveyed through said apparatus twice passes over said unit as the direction `of movement of such piece is reversed by said conveyor means,

(E) said neutralizing unit comprising (1) an elongated generally flat plate having a channel extending transversely thereof opening to one face of said plate,

l(2) means adjacent the upper edge of said plate for securing said plate in said apparatus,

(3) other means adjacent the lower edge of said plate for engagement with predetermined portions of said apparatus for supporting said plate generally upright in said apparatus but with said face at a predetermined angular relationship relative to the vertical,

(4) a lip extending transversely of said plate above said channel and projecting from said face,

(5) a charge attracting bar in said channel and extending therealong, and

('6) insulating means between said bar and said plate,

(7) said lip precluding contact of flatwork pieces with said bar as such pieces pass said plate during a charge neutralizing operation.

3. The combination of claim 2l in which said apparatus further includes (5) mounting means thereon for supporting said neutralizing unit including projecting brackets extending inwardly from opposed side framework panels of said apparatus,

and in which said other means of said neutralizing unit comprises,

(a) bumper members engaged with said brackets and supporting said neutralizing unit generally rupright in said apparatus but at said predetermined angular relationship relative to the vertical.

4. In combination, apparatus for folding flatwork pieces, and means in conjunction with said apparatus for neutralizing electrical charges picked up by said pieces during travel through said apparatus;

(A) said apparatus comprising (1) means for conveying a series of successive flatwork pieces through said apparatus past a primary fold station and a cross fold station,

(2) means at said stations for forming primary and lcross folds in each successive piece of said series,

(3) sensing means for activating said folding means when a piece is properly oriented at a given station,

(4) said conveying means at said primary fold station carrying a portion of each successive piece in a first direction past a reference location and then in a reverse direction past said reference location as a primary fold is formed therein;

(B) said neutralizing means comprising an electrical charge neutralizing unit capable of attracting and neutralizing the electrical charges carried by said pieces,

(C) said neutralizing unit being located closely adjacent the path of travel of said series of pieces through said apparatus on said conveyor means,

(D) said neutralizing unit being positioned at said reference location adjacent said primary fold station so that a portion of each successive piece conveyed through said apparatus twice passes said unit as the direction of movement of such piece is reversed by said conveyor means,

(E) said neutralizing unit comprising (1) an elongated generally tlat plate having a channel extending transversely thereof opening to one face of said plate,

(2) means adjacent an upper edge of said plate for securing said plate in said apparatus,

(3) other means adjacent a lower edge of said plate f or engagement with predetermined portions of said apparatus for supporting said plate in said apparatus,

(4) a lip extending transversely of said plate adjacent said channel and projecting from said face,

(5) a charge attracting bar in said channel and extending therealong, and

(6) insulating means between said bar and said plate,

(7) said lip precluding 'contact of flatwork pieces with said bar as such pieces pass said plate during a charge neutralizing operation.

5. In combination, ilatwonk folder apparatus for forming at least one primary fold and at least one cross fold in successive pieces of ilatwork carried though said apparatus, and means for neutralizing electrical charges picked up by said ilatwork pieces during travel through said apparatus;

(A) said apparatus including (1) means for conveying successive atwork pieces to and past primary fold and cross fold stations,

(2) means at said stations for forming primary and cross folds in successive ilatwork pieces conveyed therepast, and

(3) means for sensing the presence of successive atwork pieces at said stations and for actuating said fold forming means thereat in timed sequence;

(B) said neutralizing means comprising an electrical 16 charge neutralizing unit lcapable of attracting and absorbing an electrical charge from each atwork piece being carried through said apparatus by said conveying means,

(C) said neutralizing unit being located closely adjacent the path of travel of said successive pieces so that its neutralizing effect is directed into such path of travel,

(D) said neutralizing unit being positioned at a location in advanceof lsaid cross fold station and beyond the station at which a first primary fold is formed in each of said pieces,

(E) said neutralizing unit comprising (l) an elongated generaly flat plate having a channel extending transversely thereof opening to one face of said plate,

(2) means adjacent an upper edge of said plate for securing said plate in said apparatus,

(3) 4other means adjacent a lower edge of said plate for supporting said plate in said apparatus with said face at a predetermined relationship relative to the vertical,

(4) a lip extending transversely of said plate above said channel and projecting from said face,

(5) a charge atracting bar in said channel and extending therealong,

(6) and insulating means between said bar and said plate,

(7) said lip precluding contact of atwork pieces with said bar as such pieces pass said plate 'during a charge neutralizing operation.

References Cited UNITED STATES PATENTS 2,083,478 `6/1937 Simons 317--2 2,163,294 `6/1939 Simons 317-2 2,751,222 6/ 1956 Dexter 27OL-8l 2,993,693 7/1961 Buss et al 270-69 EUGENE R. CAPOZIO, Primary Examiner.

P. V. WILLIAMS, Assistant Examiner.

U.S. C1. X.R.

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