US2750188A - Workpiece feed control mechanism - Google Patents

Description

June 12, 1956 F. J. ROUAN 2,750,183

WORKPIECE FEED CONTROL MECHANISM Filed Jan. 2, 1953 2 Sheets-Sheet 1 Q5 47 l 33 J L 1g 23 37 3 2 1- I I E I 29 51 1 1 |1 49 J I I n I I 3 b l 51- 59 5 15 i I 53 L {E I 1 75 i 7O 7 INVENTOR I fiafla/s fauQn ATTORNEY June 12, 1956 F. J. ROUAN 2,750,188

WORKPIECE FEED CONTROL MECHANISM Filed Jan. 2, 1955 V 2 Sheets-Sheet 2 1N VENTOR ATTORNEY wonrrrrncn snap corsrnor. MnenANrsM Francis J. Ronan, Darien, Conn, assignor to Pitney- Bowes, Inc, Stamford, Conn, a corporation of Betaware Application January 2, 1953, Serial No. 329,221

Claims. ((1 271-56) This invention relates to the feeding in succession of sheet-like workpieces and especially to the accurate detection of the feeding of more than one sheet, even under adverse circumstances of sheet condition which would normally be misleading to detecting mechanisms.

In many machines which separate sheets and feed nited States Patent 0 ice them one by one, mechanism is provided for detecting a folded sheet, the feeding of more than one sheet at a time or other plural thickness condition of the workpiece being fed, and for stopping the machine operation until the matter can be corrected. In most cases the sensitive operation of such a device is to be desired and is sought after. It has been discovered, however, that in some instances Where the sheets are not necessarily new, e. g. in the feeding and counting of used transfers or paper money, severe difficulty is experienced in that repeated stoppages are caused by the dog-cared condition of the sheets. That is to say, in many instances small bits of the leading margins of some sheets become torn or creased so that a plural thickness condition is momentarily pre sented to the sensing mechanism and must be fed thereto if the sheet is to be fed at all. This trips the detector and stops the machine, even though a single sheet only is actually being fed. Such unnecessary interruptions to the operation of the machine may occur quite frequently if the sheets are in bad condition, and are a source of considerable annoyance and waste of the operators time.

The present invention has as its object the provision of a method for feeding sheets, and accurately arresting feeding when two sheets are fed, but in such a manner that the feed will, in most cases, still be continued without cessation when a single dog-cared sheet with a deceptive torn or folded portion is presented, and mechanism for carrying out the method.

it is a feature of the present invention that the prevention of the machine stopping action of a thickness detector in the case of a dog-eared sheet is brought about by providing a delay in the response of the sensing device, and a return to normal condition unless the excessive thickness proves to be of sustained duration.

Another feature of the invention is the employment of a rotatable drum as the sensing element, and the arranging of the response mechanism so as to operate to stop the machine only after the roller has been rotated through a given delay angle.

Still another feature of the invention is a novel presser mechanism for sheet feeding which cooperates with the detector drum to provide a firm, fiat feed of the sheets as they pass the detection point, and which is readily and significantly retractible to provide for easy withdrawal of offending sheets whenever the machine is automatically stopped.

With the above and other objects in View, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that various changes in the precise embodiment of the invention herein disclosed may be made Patented June 12, 1956 within the scope of what is claimed without departing from the spirit of the invention.

A preferred embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a sectional elevation of a sheet separating and feeding mechanism according to the present invention, taken substantially on line 11 of Fig. 2.

Fig. 2 is an oblique bottom view of the device of Fig. 1 looking in the direction of arrows 2-2 of Fig. 1.

Fig. 3 is an end elevation of the machine according to the present invention, illustrating especially the mechanism for stopping the sheet feed when the detector is actuated, parts being broken away to illustrate details of the structure.

Fig. 4 is a condensed front elevation of the device of Fig. 3 taken from the left and looking towards the right in Fig. 3 with the feed plate removed, and parts being broken away or sectioned to illustrate the details.

Fig. 5 is a section taken on line 5-5 of Fig. 4.

In the accompanying drawings, the invention is shown as applied to a sheet separating and counting machine somewhat similar to that shown and described in the United States patent to L. Scher, 2,378,250, although it will be understood that other applications of the invention can be made without departing from its scope as defined in the subjoined claims.

Referring to the drawings, reference numeral 11 indicates a frame member constituting a portion of a frame which carries an upwardly sloping feed plate 13 on which the sheets are stacked on edge to be conducted to the sheet separating mechanism. The supply stack of sheets (not shown) is urged up the plate by a pusher 15 and into contact with a booster roller 17 and an automatically operated separating and feeding roller 19, both rotating in the same direction, i. e. in a direction tending to draw the foremost sheet of the stack downwardly through a gap 2t) between the extreme edge of the feed plate 13 and the separating roller 19.

The feed plate carries one or more slide bars 21 which may be adjusted and clamped in any suitable manner (not shown) to space their ends 21a a desired distance from the surface of roller 19 and thus adjust the width of the gap 20 so that only one sheet at a time, of the thickness being handled, will be drawn from the supply stack of sheets and fed downwardly.

It happens infrequently, due to sticking of sheets, slight variations in sheet thickness, or other causes, that more than one sheet at a time will be forced through the gap 29, and the machine is provided with a detection means and stop mechanism for insuring that the automatic feed will be stopped whenever such an inadvertence occurs.

The detection mechanism comprises a feeler surface spaced from the surface of the roller 19 to provide a gap 22 sufiicient to pass a single sheet of standard thickness with comparative freedom, but so that if a thickness of about two sheets or slightly less should attempt to pass, the friction on the feeler surface would be suflicient to affect the feeler surface and trip the stop mechanism.

In the structures heretofore employed, the tripping of the stop mechanism by the feeler surface has been so arranged as to take place instantaneously upon actuation of the feeler surface with a very sensitive and quick response. It has been discovered, however, that when sheets of a dog-cared character, e. g. used paper money or transfers are being handled by such devices, the frequent small folded flaps, which develop from various causes such as short tears into the margin, operate to provide a superthick condition sufficient to trip the stop mechanism quite frequently. The machine is thus often stopped erroneously when a single bill or sheet only is actually being separated and fed. To prevent this inconvenience and provide sustained feeding even when dog-eared sheets are being handled, the present invention employs a method of using a sensitive feeler mechanism, but delaying its tripping response for an instant after first contact and permitting the feeler to restore itself to unoperated position without tipping the stop mechanism unless the length of superthick material passed is a certain predetermined minimum. Thus all superthick conditions due to short tears and dog-eared sheets will be overlooked by the machine, while only actual feeding of doubled sheets or severely abnormal folded conditions will cause the machine to stop.

The feeler surface of the present invention is arranged for delayed action by making the same in the form of a wheel or drum 23 which cooperates with roller 19 to determine the size of gap 22. The drum 23 is rotatably carried by a shaft 25 which is mounted in the end of a slide bar 27, slidable adjacent the under surface of feed plate 13. The slide bar 27 tends to be urged towards the roller 19 by a compression spring 29, and may be clamped in any desired location by means of a screw 30 which controls the jaws of a clamp 31 arranged to grip the bar 27. A manual control button 33 on the end of the bar 27 is provided for drawing it outwardly against the force of spring 29.

When a workpiece of sufficient thickness is introduced into the gap 22 to cause actuation of the detection surface, i. e. drum 23, the drum is caused to rotate about its axis through an angle which corresponds to the length of contact with the plural-thickness article being fed, measured along the drum periphery. The drum 23 is normally held in a starting or zero position by a torsion spring 35 which has one arm engaged against the bar 27 and the other engaging a stud 37 on the drum. This starting position is determined by a stop pin 39 which engages against the arm 27 and limits rotation of the drum 23 in a return direction. The spring 35 is designed to provide a suitable torque on the drum 23 in an antifeeding direction so that when a gap setting of gap 22 is arrived at as hereinafter described using a double sheet, a normal single thickness will have no tendency whatever to rotate the drum, while a normal double sheet thickness will move the same very readily against the force of spring 35.

A portion of the periphery of drum 23 is notched out and thus provides a radial striking surface 41 designed to engage and trip the stopping mechanism of the machine, to be hereinafter described in detail, and the initial element of which is the finger 43 on collars 45, mounted on a transfer rock shaft 47. It can be seen that, in the particular arrangement shown in the drawing, the drum must be rotated through about 36 (corresponding actually to about /2 inch of drum periphery) before the striking surface 41 engages and moves the finger 43. This, then, provides the delay period which the detecting mechanism, although sensing a plural thickness workpiece fails to trip the stop mechanism to shut down the machine. If the workpiece being fed is truly a double sheet, or a sheet so badly damaged or folded that a marginal folded part of over /2 inch in length is present, then the striking surface 41 will ultimately impinge on finger 43 to trip the stop mechanism. If, however, the sheet is merely dog-eared and has a short folded-back flap of less than one-half inch, the drum 2.3 will follow the doubled portion of the sheet for as long as it continues in contact with the drum, and as soon as a single thickness only is again encountered, the drum will be released to be returned to starting position by the spring 35. The sheet will then continue to feed in the normal manner.

While the description has proceeded on the basis of half inch being a desirable value for the feed delay in stoppage actuation, it will be understood that this figure is not limiting since a feed delay of much shorter distances would eliminate many of the unnecessary stoppages under ordinary circumstances and would be operative for the purposes of this invention.

From an inspection of Figs. 1 and 2 it will be seen that setting of the correct size for gap 22 can be quickly made by loosening clamp screw 30, drawing outwardly on button 33, placing a suitable thickness of material (e. g. two sample pieces of the sheet material to be fed) between the drum 23 and roller 19, and then releasing button 33 and allowing the spring 29 to return the bar 27 until movement stops. This will give a reliable friction driving grip of the surface of drum 23 against an element of double sheet thickness and still permit a single thickness to pass freely through the gap 22. The setting can then be secured by retightening the clamp screw 30.

To maintain a reliable feed of the sheets at all times and to retain the sheets in proper position for coaction with the detecting means, the present invention provides a novel cooperative presser action. As can be seen from Figs. 1, 2 and 4, separation of the sheets is brought about by the separating roller 19 together with a pair of closely adjacent rollers 49 and 51, all three being of substantially equal diameter in fact forming portions of a single feed roller surface, since all are mounted on and driven by a main feed shaft 53 rotatable on the frame member 11. After the separation point at gap 20 is passed by the sheet, however, the surface of roller 19 then acts primarily as a datum surface opposing the detector drum 23 for measurement of sheet thickness. For continued reliable feed, of the separated sheet reliance is placed on the rollers 49 and 51 which are opposed by a presser mechanism including a pair of presser rollers 55 and 57. These rollers are substantially equal in diameter to the detector drum 23 so as to present an entrance throat of substantially the same character at all points to an oncoming sheet. The rollers 55 and 57 rotate on a common shaft 59 carried by one end of a reciprocable bar 61 which is arranged to move so that axis of shaft 59 travels substantially radially of the wheels 49, 51. This is effected in the present instance by a pair of links 63, 65 which are pivotally connected to the bar 61 and to their supports on the underside of feed plate 13. The links are also arranged so that the line joining the pivots of each link is substantially perpendicular to the axis of bar 61 at the time when the rollers 55 and 57 are in contact with rollers 49 and 51. Thus the motion of the presser rollers 55, 57 at this point is almost exactly a straight line towards and away from the axis of rollers 49 and 51 with substantially no peripheral component. A tension spring 67 connected between the arm 65 and an anchor 69 on the underside of the feed plate urges the presser rollers 55 and 57 into sheet feeding relationship with the feed rollers 49 and 51. The arrangement thus provided permits a substantial amount of free movement of the presser rollers in a withdrawal direction to permit prompt freeing of the sheets from the feed grip when more than one sheet is inadvertently fed. The readily accessible end of the long link 65 also provides a convenient actuating means in this connection, all of which contributes to a rapid return of the machine to a restartable condition whenever a stoppage occurs, as will presently be described.

A stop mechanism is provided for arresting the feeding action when more than one sheet starts to feed through and comprises means for locking the shaft 53 against rotation.

When the drum 23 has been rotated through a sufficient angle (about 36 in the present case) its striking surface 41 moves the finger 43, thus rocking the shaft 47 clockwise as seen in Fig. l. A crank 70 on the shaft 47 acts on a link 71 which through a crank 73 carried by a control rock shaft 75, rotates the latter. The control rock shaft carries a tappet 77 which acts on the end of a lever 79 (Fig. 3) to raise the same and thus move an integral latch finger 81 to the right. The lever 79 and latch finger 81 are rockably mounted on frame member 11 and are normally urged in a counterclockwise direction by a torsion spring 83. They are movable against the action of this spring by tappet 77.

a'rsonss The latch finger 81 is normally engaged with a brake finger 85 rockable on the feed shaft 53 and urged in a brake applying direction by a spring 87, butheld in brake release position by the latch finger. A floating brake member 89 is supported at one end 90 in an opening 91 of a plate 93 which is freely rockable on the frame member 11. As a convenient measure for the support of the plate 93 together with that of other members to be hereinafter described, there is provided a fixed bushing 5 which surrounds the feed shaft 53 and projects outwardly from the face of frame member 11, towards the right as seen in Fig. 4. The other end of the brake member 39 has a pair of integral arms 97 which embrace the brake finger 85 and support the brake member 89 loosely thereon. An intermediate portion of the brake member 89 is notched as indicated by reference character 99 to receive a peripheral portion of a brake disc 101 which is rigidly secured to the feed shaft 53 to rotate therewith. The brake member 39 has a restricted floating movement as determined by a pair of adjustable stop arms 163, 105 secured respectively by integral collars 107, 109 to the fixed bushing 95, and arranged to lie adjacent the brake member 89, one on either side.

The plate 93 is so shaped and weighted that it tends to revolve counterclockwise as seen in Fig. 5, thus locating the end portion 91 of brake member 89 firmly in a position determined by the setting of stop finger 103. The parts are so related and adjusted that when the end 90 of the stop member is thus located, and when the brake finger is retained by the latch finger 81, the notch 99 of the brake member allows free rotation of the disk 101 therethrough. However, when the latch finger 81 is released as previously described, the spring 87 acts through brake finger 85 causing the brake member 89 to cant slightly. The walls of notch 99 then bind securely on the faces of disk 101 and cause instantaneous stoppage of the rotation of feed shaft 53.

In order to provide for quick resetting of the stop mechanism after it has been tripped, a reset arm 111 is pivoted on the frame member 11, and includes a pusher 113 for engaging against the side of the brake member 89 and swinging it to a position to bring brake finger 85 under latch finger 81. A manual operating element 115 projects to a convenient position for manual engagement, and control finger 117 strikes against suitable stops 119 and 121 which appropriately limit the throw of the reset arm, the latter being weighted so as normally to rest with control finger 117 against stop 119 when not in use.

It may be explained that shaft 53 receives its rotary action from a source of power (not shown) through a train of mechanism which includes the drive gear 123 meshing with the pinion 125 which is rotatable on the shaft 53 and carries an axial pin 127 drivingly engaged in the notch 129 of a friction clutch 13.1. The clutch 131 frictionally grips a sleeve 133 which is rotatable on the shaft 53 and is rigidly connected at one end to the inner member 135 of a one-way roller clutch 137. The roller clutch has an outer member 139 rigidly secured to the shaft 53 as by set screw 141. The booster roller 17 is shown as driven from a gear 143 afiixed to shaft 53, through idler 145 and pinion 147 (Fig. 3).

When the machine is operating normally, the one-way clutch 137 provides for driving the feed rollers 49, 51 in a feeding direction (counterclockwise as seen in Fig. 3), but permits the feed rollers to overrun the drive in case the fed sheet is taken away by a subsequent feeding mechanism at higher speed, as is conventional sheet feeding practice. When the stop mechanism is operated and brake member 89 arrests disk 101 and shaft 53 to stop the feed, the overrunning clutch 137 (including integral sleeve 1.33) is also prevented from further counterclockwise rotation, and the driving motion of gear 125 is allowed to continue by reason of the slipping action per- 6 mitted at the connection of the friction clutch 131 with the surface of sleeve 133.

From the foregoing description it can be seen that the present invention provides a method and machine for separating and feeding sheet-like work ieces one-by-one from a stack of workpieces, including the detecting of inadvertent feeding of more than one sheet at a time and stopping in the machine at such times, said detection being extremely sensitive in operation, but also capable of avoiding the inconvenience of stoppages in practically all cases where a double thickness condition is local and results purely from the dog-eared condition of the sheet being fed. A feeding arrangement directly related to the detection means in a novel manner so as to provide reliable feeding, accurate detection, and ready release of improperly fed sheets is also a consideration provided for by the present invention.

Having described the invention what is claimed is:

1. In a device for counting, printing or otherwise operating upon separate tickets, checks or other workpieces, an automatic feed mechanism for advancing the workpieces in succession past a sensing station to an operating station; a thickness sensing device at said sensing station for testing the thickness of the workpieces during feeding by said feed mechanism including a backing-up surface and a rotatable workpiece contacting drum having a normal rotary starting position, said drum being settable to a position with respect to said backing-up surface such that the drum will not be rotated by a passing single workpiece of normal thickness, but will be frictionally engaged and rotated by a folded workpiece or a plurality of superposed workpieces being advanced; means for stopping said feed mechanism; a striking surface on said drum; and trip means for operating said stopping mechanism having a part arranged in the path of said striking surface when the drum rotates but initially spaced from said striking surface a predetermined distance to provide a delay corresponding to a determine feed length of the workpiece prior to tripping action.

2. In a device for counting, printing or otherwise operating upon separate tickets, checks or other workpieces, an automatic feed mechanism for advancing the workpieces in succession past a sensing station to an operating station; a thickness sensing device at said sensing station for testing the thickness of the workpieces during feeding by said feed mechanism including a backing-up surface and a rotatable workpiece contacting drum hav-- ing a normal rotary starting position; spring means tending to return said drum to said rotary starting position, said drum being settable to a position with respect to said backing-up surface such that the drum will not be rotated by a passing single workpiece of normal thickness, but will be frictionally engaged and rotated by a folded workpiece or a plurality of superposed workpieces being advanced; means for stopping said feed mechanism; a striking surface on said drum; and trip means for operating said stopping mechanism having a part arranged in the path of said striking surface when the drum rotates but initially spaced from said striking surface a predetermined distance to provide a delay corresponding to a determinate feed length of the workpiece prior to tripping action.

3. In a device for counting, printing or otherwise op erating upon separate tickets, checks or other workpieces, an automatic feed mechanism for advancing the workpieces in succession past a sensing station to an operating station; a thickness sensing device at said sensing station for testing the thickness of the workpieces during a rotatable workpiece feeding and feeding by said feed mechanism including a backing-up surface and a rotatable workpiece contacting drum having a normal rotary starting position, said drum being settable to a position with respect to said backing-up surface such that the drum will not be rotated by a passing single workpiece of normal thickness, but will be frictionally engaged and rotated by a folded workpiece or a plurality of superposed workpieces being advanced; means for stopping said feed mechanism; a striking surface on said drum; and trip means for operating said stopping mechanism having a part arranged in the path of said striking surface when the drum rotates but initially spaced from said striking surface a predetermined distance to provide a delay corresponding to a determinate feed length of the workpiece prior to tripping action.

4. In a device for counting, printing or otherwise operating upon separate tickets, checks or other workpieces, a frame; an automatic feed mechanism for advancing the workpieces in succession past a sensing station to an operating station; a thickness sensing device at said sensing station for testing the thickness of the workpieces during feeding by said feed mechanism including a backing-up surface and a workpiece contacting drum having portions with a normal rotary starting position, said drum being settable to a position with respect to the backing-up surface such that the drum will not be rotated by a passing single workpiece of normal thickness, but will be frictionally engaged and rotated by a folded workpiece or a plurality of superposed workpieces being advanced; means for stopping said feed mechanism; a striking surface on said drum; trip means for operating said stopping mechanism having part arranged in the path of said striking surface when the drum rotates but initially spaced from said striking surface a predetermined distance to provide a delay corresponding to a determinate feed length of the workpiece prior to tripping action; and means supporting said drum for adjustment towards and 8 away from said backing-up surface comprising an element carrying said drum and slidable on said frame, a spring urging said element towards said backing-up surface, and a clamp for fixing the proper adjusted position when determined.

5. In a machine of the character described; automatic means including a roller surface for normally separating tickets, checks or other workpieces one at a time from a supply stack of workpieces and feeding them insuccession along a predetermined feed path; means for stopping the operation of the roller surface; a detector drum positioned adjacent but slightly out of contact with a portion of said feed roller surface for gauging the thickness of pieces being fed; means to actuate said stopping mechanism in response to rotation of said drum through a predetermined angle; and means to adjust the spacing between said drum and said roller surface comprising an element slidable towards and away from said roller surface; and carrying said drum; means urging said element towards said surface; and a clamp for securing the adjustment when effected.

References Cited in the file of this patent UNITED STATES PATENTS 663,672 Dexter Dec. 11, 1900 2,129,230 ONeil Sept. 6, 1938 2,175,167 Davidson Oct. 10, 1939 2,273,288 Rouan Feb. 17, 1942 2,318,132 Welk May 4, 1943

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