US961586A

US961586A - Paper-feeding machine.

Info

Publication number: US961586A
Application number: US45514508A
Authority: US
Inventors: Talbot C Dexter
Original assignee: Dexter Folder Co
Current assignee: Dexter Folder Co
Priority date: 1908-09-28
Filing date: 1908-09-28
Publication date: 1910-06-14
Anticipated expiration: 1927-06-14

Description

v T; C. DEXTER.

PAPER FEEDING MACHINE.

' APPLIOATNN rnnn 31:21-28, 1908.

Patented June M, 1910.

6 BKEETB-BHEET 1.

T. G. DEXTER. PAPER FEEDING MACHINE.

APPLICATION FILED SEPT.

' Patented June 14,1910.

6 SHEETS-SHEET 2.

. T. 0. DEXTER. PAPER FEEDING MACHINE. APPLICATION FILED SEPT. 28, 1908.

Patented June 14,1910.

T. C. DEXTER.- PAPER FBEDINGMAOHINE. APPLICATION mum 92M. 2a, 1908.

Patented June14,1910.

5 SHEETS-SHEET 4.

Isl ull.

I T. G. DEXTER. PAPER FEEDING MACHINE. APPLICATION FILED SEPT. 2a, 1908.

9m 56, Patented June 14,1910.

5 SHEETS-SHEET 5.

' manor 0. DEXTER,

FTQ

OF PEARL RIVER, NEW YORK, ASSIGNOR TO DEXTER FOLDER COMPANY, OF PEARL RIVER, NEW YORK, A CORPORATION OF NEW YORK.

PAPER-FEEDING MACHINE.

senses.

Specification of Letters Patent.

Patented June 14., rate.

Application filed September 28, 1908. SerialNo. 455,145.

To all whom it may concern.

Be it known that I, TALBOT .C. Dnx'rnm'a citizen of the United States, residing at Pearl River, in the county of Rockland and State of New York, have invented certain new and useful Improvements in Paper- Feeding Machines, of which the following is a specification.

My present improvements relate generally to the type of machine in which a-bank or supply of heet-s .is intermittently fed in fanned out condition to suitable separating and feeding devices, which complete the separation of the successive sheets and pass them to suitable sheet delivery mechanism, which will move the sheets from the bank or supply and pass them to the machine, such as the printing press or, folding machine, which is to operate upon them.-

My present invention relates particularly to novel means for controlling the operation of the bank feedin mechanism to insure the proper position of sheets beneath the sep-, arating and feeding devicesevery time they are thrown into action.

In this type of machine a great deal of difliculty has been encountered in regulating or controlling the intermittent feed of the bank of sheets to the separating and feeding devices. It is necessary that the feed of the bank of sheets shall take place during the interval that the separating and feeding devices are operating. It has been proposed in the past. to regulate the feed of the bank in various ways. In some cases this bank feed has been controlled by the same automatic devices which control the throwout of the separating and feeding devices. In other cases, the bank feed has been controlled by the height of the feeding devices above the sheet support when the feeding devices are operating. In still other cases the bank feed has been regulated by the separating and feeding interval or length of time that said separating and feeding devices are in action upon the sheets. There are certain disadvantages to all of thesemethods of controlling the feed of the bank of fanned out sheets to the separating and feeding devices which causes trouble in the operation of the machine under certain conditions, which disadvantages I have found are due mainly to the fact that the element of control heretofore adopted is not a proper indication of the condition rcquiring the continuance or discontinuance of the feed of the bank of sheets.

In machines of the type under discussion as now constructed, the separating and feed ing devices which act upon the fanned out bank of sheets are in the form of-combing -wheels which are rapidly revolved in engagement with the top sheet of the bank. The action of these combing wheels is most pronounced upon the top sheet of the bank, but all of the sheets resting beneath the combing wheels are affected to a gradually decreasing extent to increase the fanned out condition of the sheets. The combing wheels under the control of automatic sheet top sheet until said to sheet reaches registered position, when tie combing'action is arrested. It is necessary for the proper operation of the machine, that the interval of action of the combing wheels be limited in order that the operation of the several parts of the machine may be properly timed to produce the desired result, so that the success or failure of the combing devices in properly feeding a sheet to registered position during any interval of combing, must necessarily depend upon the distance of the leading edge of the, sheetacted upon from the gages or sheet delivery mechanlsm at the time the combing action is started. Since the position of each successive top sheet at the start of the combing action upon it, is determined either by the previous action of the bank feeding mechanism or of the'combing devices. (the bank feeding mechanism supplementing the action of the combing devices to place the successive sheets in proper position on the combing devices) it naturally follows that the necessity for causing the operation of the bank feeding mechanism to place the leading edge of a sheet with in the required distance of the gages or delivery mechanism to be successfully carried up to the delivery mechanism by the subsequent action of the combing devices, is most accurately determined by the position of the. sheet itself. For these reasons I have devised a mechanism for controlling the operation of the feed of the bank of sheets. in which the position of the top sheet just prior to the start of a combing operation shall determine whether or not the bank of sheets shall be given another feeding impulse.

actuated devices, remain in action upon the In carrying out my invention, I have arran ed an intermittently operating feeding mec anism for the bank of sheets, with suitable controllin devices normally preventing the operation of said feeding mechanism, and including a detecting device, which detects the presence'or absence of a sheet 1n a required normal position, to cause the o eration of the bank feed in the event that t e sheet has not been moved forward sufficientl to be properly registered by the succee ing combing operation, and to continue to hold the bank feed out of operation in case the sheet has reached a position from which the combing devices can carry it into registered position. In a broad sense my invention may be considered as the combination with mechanism forfeeding a bank of sheets to a suitable separating and feedin device, of means for throwing said ban feeding mechanism into action when the leading edge or portion of the bank of sheets is more than a predetermined distance from the ages or sheet delivery mechanism of the mac ine.

More specifically the preferred embod1- ment of my present invention comprises a feeding machine having an intermittently operated pawl and ratchet feeding mechanism for the bank of sheets, a controller for normally preventing the action of said mechanism, a detector arm connected with said controller and resting above the path. of sheets, and a depression or notch arranged in the feed table beneath the path of sheets at a proper distance from the gages, said detector arm being operated after each sheet is carried away by the delivery mechanism, and before the commencement of the succeeding combing action, to engagesaid notch or depression in the event that the succeeding sheet has not moved forward sufliciently to cover said notch or depression, to restrain said controller and permit the operation of the bank feeding mechanism, or to rest upon and slide on said succeeding sheet, in the event that said sheet has been moved forward sufiiciently to cover said notch or depression, and thereby permit said controller to prevent the operation of said bank feedin mechanism.

rom this description it will be observed that in accordance with my improved mechanism for controlling the operation of the bank feeding mechanism, the position of the next sheet beneath the one that is" being separated, determines whether or not the bank of sheets shall be given a feeding impulse.

In order that my invention may be fully understood, I will first describe the same with reference to the accompanying draw ings, and afterward point out the novelty more particularly in the annexed claims.

In said drawings Figure 1 is aside elevation of a paper feeding machine embodying my invention. Fig. 2 is a plan view of part of the said machine showin my improvements F1g. 3 is a longitu inal sectional elevation, with parts broken away and parts omitted, showing my im roved controller for the bank feeding mec anism. In this view the parts are shown in the position assumed just prior to the action of the automatic controller. Fig. 4 is a similar view showing another position of the parts, the r presence of the leading edge of the top sheet of the bank being in proper position for the operation of the separating and feeding devices and the controller holding the pawl and ratchet mechanism out of operation. Fi 5 is a similar view showing another position of the parts, the leading edge of the top sheet being more than the predetermined distance from the gages or delivery mechanism, and the controller being held out of action to permit the operation of the awl and ratchet feed for advancing the feathered bank of sheets.

Paper feeding machines of the type shown in the accompanying drawings to which my present improvements have been applied, include two distinct. sheet feeding an separating mechanisms, namely, first the means for gradually forwarding and fannin out a bank of sheets b passing 95 them rom a supply table to a eed table, and presenting them in reversed position upon the feed table; and second, a final separating and feeding mechanism which successively detaches single sheets from the fanned out bank or plle and passes the individual sheets to deliver mechanism, which forwards the'sheets to t, e machine which .is

to operate upon-them.

In theaccompan ing drawings which illustrate this type 0 machine with my im provements embodied therein, 1 is a supply table mounted in inclined position upon the side bracket frames 2 directly above a feed table 3 which is suitably mounted in the base side frames 4 of the machine. The supply table 1 is inclined downwardly toward the rear, while the feed table 3 is inclined downwardly toward the front.

Passing longitudinally over the inclined supply table 1 are the heavy endless feed belts 5 which pass around the supporting pulleys 6 and driving pulleys 7. The supporting pulleys 6 are mounted upon a shaft 8 which is journaled in brackets 9 secured beneath the upper forward end of the supply table 1. The driving pulle s 7 are mounted upon transverse shaft 10 yonrnaled in the side bracket frames 9. A. series of tension guiding pulleys 11 are mounted upon a transverse shaft 12 which also journaled inside bracket frames 2.

Keyed to the shaft 10 is a gear wheel (not shown) meshing with a similar driving gear wheel 16 keyed on a driving shaft 17 which (senescis journaled at its opposite ends in the side bracket frames 2. This driving shaft 17 is intermittently operated by a pawl and ratchet mechanism through means which will presently be described.

Passing lon itudinally over a portion of the lower fee table 3 1s a series of heavy feeding belts 20 which are mounted upon a series of supporting and driving pulleys 21 and 22mounted respectively on the

transverse shafts

23 and 24, suitably 'ournaled in the base frame 4. It will be understood that the

pulleys

21 and 22 are mounted in slots formed in the feed table 3, so as to permit the feed belts 20 to pass above and below the table around said pulleys. A series of tension and guiding pulleys 25 is mounted upon transverse shaft 26 suitably journaledin the v said base frames 4 in (position to engage and guide the endless fee belts 20.

Keyed to the shaft 24 is a gear wheel 26 which meshes with a similar intermediate gear 27 journaled on one of the side bracket frames 2 at 28, and in turn meshing with and driven from the gear 16 on driving shaft 17. From this described arrangement it will be observed that the rotation of driving shaft 17 imparts motion simultaneously to the endless feed belts 5 and 20 for forwarding and fanning out a bank of sheets. As usual with the type of machine under discussion, a curved throat is provided to communicate between the rear ends of the upper and lower tables. In the machine shown in my drawings, a series of stationary curved guide plates 35 are mounted at intervals upon a transverse stay rod 36, which is supported at its opposite ends in the side bracket frames 2. Said guide plates 35 form continuations of the surface of the supply table 1. The lower ends of these curved guide plates 35 terminate above the rear end of the feed table 8 a sufiicient distance to permit the free passage between said ends of the guide plates and the feed table, of a combed out ile or bank of sheets.

T e rear wall of the curved throat communicating between the supply and feed tables is formed in my machine of sectional curved guides 40, mounted upon cross stay rods 41, suitably supported from the side bracket frames 2. The upper ends of these curved guides 40 extend forwardly beyond a cross shaft or bar 45 movably mounted in the side bracket frames 2 and carrying the forwardly projecting arms 46 formed with vertically arran ed elongated slots 47, in which are loosely ournaled the transverse shaft 48 carrying a series of pressure rollers 49 which are designed to rest in contact with the upper surface of the combed out pile of sheets to assist in guiding the leading edges of the upper sheets beneath the upper ends of the rearcurved guides 40 as the bank of sheets starts to curve downwardly into the communicating throat. These forwardly projecting arms 46 carry pressure shoes 50 having forwardly extending curved spring guiding fingers or blades 51, which guide the leading edges of the top sheets of the bank beneat the peripheries of pressure rollers 49, so as to avoid-the possibility of bending back or folding the edges of the sheets as they pass into the communicating throat. The arms 46 are preferably rigidly fixed to the transverse shaft 45 so that by rotating the shaft 45 to the rear by taking hold of one of the arms 46, the pressure rollers 49 and shoes 50 --may from their engagement with the pile of sheets.

Returning now to the consideration of the mechanism for driving the series of feed belts which pass over the surfaces of the supply and feed tables, it will be observedthat a ratchet wheel 65 is keyed to the driving shaft 17, and that a driving pawl 66 ivotally mounted at 67 in the end of a roe arm 68 rests by gravity inengagement with the ratchet wheel 65. The pawl carrying rock arm 68 is journaled upon the driving shaft I7, and has depending therefrom a rigidly connected rock arm 69, pivotally connected at its lower end 70, with a forwardly extending rod or pitman '74 pivoted at 75 to the lower end of a rock arm 76 keyed to a transverse rock shaft 77. This rock shaft 77 extends transversely of the feeding machine and is journaled in the side frames 78 and auxiliary frame pieces (not shown), which constitute the supporting frame of'the second separating and feeding mechanism which individualizes the sheets preparatory to forwarding them from the machine.

The rock shaft 77 carries an upwardly projecting rock arm 80 having a freely journaled antifriction roller 81 operatlng in peripheral contact with cam 82 mounted on a cam shaft 83, suitably journaled in the machine frame.

Depending bracket arm 71 is adjustably secured to the rod or pitman 74 and carries a rod 72, which passes freely through a guide bracket 73 on the side frame 4, and supports an expansion spring 72 which is confined between the bracket arm 71 and the guide bracket 7 3. This spring 72 imparts the r ee turn motion to the pawl carrying arm 68, 6t), and causes the antifriction roller 81 to follow the periphery of cam 82, excepting when the return movement is resisted by the controlled mechanism hereinafter explained.

From this description it will be observed that by the cam 82 operating through

rock arms

76 and 80 and rod or pitman 74 and the pawl and ratchet mechanism described, the driving shaft 17 will be intermittently rotated for imparting feeding motion to the endless belts 5 and 20. Without any governor or controlling device, this belt operating mechanism would operate continually which would cause the bank of sheets to be shaft 83. This cam fed too rapidl to be taken care of by the separating an feeding devices which individualize the sheets. culty, I have devised the'improved governing mechanism controlled by the position of each sheet just before it is acted upon by the combers for determining whether or not the bank feed mechanism will operate.

The arrangement of the spring 72 for returning the pawl carrying arm and holdin the cam operated arm in en a ement wit the cam, permits the arrestet e pawl carrying arm at the limit of its forward or feedlng stroke without interference with the continued rotation of the cam 82 above referred to. This. dependin rock arm 69 is formed with a notched s oulder 85 with which a stop finger'or dog 86 is adapted to engage to prevent the return movement of the pawl carrying rock arm. This stop finger or dog 86 projects from a hub 87 mounted upon a short shaft. 88 journaled in the side bracket frame 2. A stop lug 89 projects from the hub 87 into engagement with the stop lug 90 upon the machine frame limiting t e downward motion of the dog 86, a

tenslon spring 91 connecting the hub 87 withd a pin on the machine frame for holding said dog 86 in its downward disengaged position with a yielding pressure.-

95 is a rock arm pivoted at 96 to the ma-' chine frame 4, and formed at its upper end with a tap et or projection 97, which is adapted to he periodically thrown into enga ement with a lug 94 projecting from the hu% 87 of dog 86, to move the dog 86 into the path of the notched shoulder 85. Rod 98 is pivoted to rock arm 95 at 98, and

passes through guide bracket 99 upon the machine frame and supports expansion spring 100 confined between bracket 99 and rock arm 95 for tending to move said rock arm 95 into engagement with the dog controllin lug 94. This normal action is periodica l resisted by the controlling mechanism w ich will now be explained.

A rod or pitman 105 is pivoted at its rear end 106 to the rock arm 95, and at its forward end 107 to a rock arm 108, depending from rock shaft 109 journaled in bracket arms 110. This, rock shaft 109 carries two

other rock arms

111 and 112. The rock arm 111 carries in its forward end a'ntifriction roller 113 which operates in peripheral contact with a controlling cam 114 keyed to the 114 acting upon the part described normally holds the rock arm 95 away from the controlling lug of the dog 86 so that the sprin of the dog 86 will hold it out of the path 0? the shoulder 85. Since, howeveri said controlling cam has a depression or ow portion, the rock arm 95 will To obviate this difiiwhich control the'action of the feed gages and bore through it for the. reception of the rear end of a detecting rod or arm 125. This detector arm 125 is adjustably mounted in the block 120 and secured in the desired adjusted position therein by means of a thumb screw 121.

. Arrange d in the forward portion of the feed board or table 3, ad'acent to the sheet delivery mechanism an the feed gages the combing evices, is a stop shoulder 130 formed by cutting a recess or depression in the surface of the feed table. This stop shoulder 130-is arranged-a predetermined distance behind sheet delivery mechanism that which the combin evices can carr a sheet during the norma combinginterva This feeding capacity of the combing devices varies w1th different the distance being .grades of paper and different sizes of sheets,

so that I prefer to arrange a series of such shoulders as shown in the drawings and indicated at 130, 131 and 132 said shoulders being arranged longitudinally of the machine and a fraction of an inch apart so as to render the control'of the able to suit the requirements of the particular jobs. It is necessary to the detector arm 125 to suit the particular stop shoulder in the sheet support with wh ch it is to cooperate. This may be done.

by having different lengths of detector arms which can be mounted'in the block 120 or by providing some other suitable adjustment for a single detector arm. If a single detector arm is employed as shown, it will be understood that the engaging end of said arm would have to be bent downwardly to cause it to pro erly engage the shoulder under the contro of the rearwardly pro'ecting arm 135 and the antifriction roller 137.

- The series of stop shoulders 130, 131 and 132 are directly beneath the forward end of the detector arm 125 so that said arm can engage one of said shoulders in its forward movement to stop the motion ofthe rock shaft 109 and the parts connected therewith in the event that the stop shoulder-is not covered by a sheet.

The block 120 carries a rearwardly projecting arm 135, formed with an upper bevel end 136, which is adapted to engage an anti machine adj ust-' properly adj ust' or tripping fingers,

friction roller 137 journaled upon a bracket arm 138 secured to the bracket 110. The engagement of arm 135 with antifriction roller 137, upon the rearward movement of rock arm 112, raises the detector finger 125 away from the path of the sheet to hold said finger in said raised position until the rock arm 112 again moves forward.

150 represents diagrammatically one of a pair of sheet combing wheels. This combing wheel is driven in any suitable manner, such for instance as shown in my application filed September 2nd, 1908, Serial No. 453,948. The particular method of driving and controlling the combing wheels is not material to my present invention. It is, however, necessary to have some suitable sheet gaging such as illustrated diagrammatically at 160 for controlling the action of the combing wheels in the manner explained in my above named application. It is also necessary in machines of this description to have some suitable sheet delivery mechanism as explained in my above named application, such as drop roller delivery mechanism as diagrammatically indicated at 170, 171 in the bank feeding mechanism Wlll be understood from the following explanation: As stated above, the pawl carrying rock arm 68 tends to oscillate under the action of the cam 82 and spring 72*. The detector arm 125 tends to reciprocate above the forward portion of the fanned out bank of sheets upon the feed board, said reclprocation being normally caused by the controlling cam 114 and spring 100. Assuming that the bank that is to be acted upon by the combing separating and feeding devices, is in proper position for the operation of the combers as indicated in Fig. 3 of the drawings, it will be observed that the forward portion of the bank or of the top sheet of the bank, will project sufficiently near the gages or sheet delivery mechanism to cover up the depression which forms the stop shoulder 130. Thesheets being in this position, and the controlling cam tending to move the detector finger 125 forwardly, will disengage the arm 136 from roller-137, which will permit the detector finger 125 to rest upon the top sheet of, the bank and since the stop shoulder 130 is covered up, said detector fin er will slide forwardly on the sheet, and wi 1 not engage said shoulder. The forthe drawings of my present case. For regulating the length of the stroke of pulse be found necessary ward position of the detector finger 125, is shown in Fig. 4 of the drawings,- from which it will be observed that since the movement of the detector finger has not been arrested, the rock arm 111 has been allowedto follow the depression in the controlling cam 114,

which has moved forwardly the rock arm 95 into engagement with lug 94, with the result that dog 86 is moved up into the path of the notch 85 of rock arm 69, thereby preventing the spring 72" of the pawl and ratchet feeding mechanism from returning the pawl carrying arm for a new stroke, it being, of course, understood/tifit this shifting of the parts of the controller is arranged to take place just prior to the return movement of the pawl carrying rock arm. This arrangement is effected by a proper arrangement of the controlling

cams

82 and 114. If on the other hand, the bank of sheets has not been fed forward to within the predetermined distance of the feed gages or sheet delivery mechanism when the detector of the feed controlling mechanism starts to act, the first forward impulse of the detector arm 125 will drop it into engagement with the feed board, and since the leading portion of the bank of sheets is not far enough forward to cover the stop board, the end of the detector finger 125 will engage said notch and arrest the forward movement of the finger. The result of this arrest of said detector finger is shown in Fig. 5 of the drawings. The rock arm being unable to follow the depression in the controlling cam 114, it will be clear that the rock arm 95 is held against motion and the spring 91 will hold the dog 86 out of the path of the notched shoulder 85 so that the pawl carrying rock arm will have its return movement imparted to "it which insures a feeding impulse being imparted by the action of the cam 82.

The detecting device of the feed controlling mechanism to produce the best results must act just prior to each separating an feeding action of the combing devices. As the operation of feeding sheets in a machine of this type is quite rapid, it will be understood that the moment for detecting the position of the bank of sheets must be between the delivery of one separated sheet and the start of the combing action upon the next sheet. In other words, the detecting arm should be thrown into action in rear of the sheet which is passing out of the machine under the action of the delivery mechanism, and just before the combing devices are thrown into action for separating and feeding forward the succeeding sheet. The osition of the bank of'sheets being detecte before the action of the combing devices, it will be understood that should a feeding imby the detector,

shoulder130 in the feed a v of this ty the bank renders said. controlling said feedingimpulse will be quickly imparted just as the combing wheels start to act.

So far as I am aware I am the first to produce and desire to claim broadly, in. a machine of the type under consideration, a controlling mechanism for the feed of a bank of sheets in which said controlling mechanism is normally active to prevent the operation of the bank feeding mechanism in combination with means acting upon said controlling mechanism for causing t e operation of said bank feeding mechanism when the leading portion of the top sheet or of the bank is more than a predetermined distance from the gages or the delivery mechanism. I also desire to claim broadly in a machine e, the controlling mechanism for eed, in which a sheet actuated or controlled device, the combin or separating devices, determines whet er the bank feed mechanism will act. I also desire to claim broadly in a machine of this ty e, controlling mechanism for the bank fee in which the absence or presence of a sheet from the leading portion of the bank is detected and determines whether or not the bank feed will operate. I also desire to claim broadly in a machine of this type, a etc in the path of the sheets which is covered y a sheet being in roper position to prevent engagement of a etectmg arm so as to withhold the bank feeding mechanism from operation, said detecting arm being adapted to enga e said stop in the absence of a sheet or the leading portion of the bank in proper position to cause the operation of the bank feeding mechanism. In addition to these broad features which I claim to be of reat importance in view of the accuracy 0% determining the necessity for the operation of the bank feeding mechanism, I desire to claim the specific details of the particular embodiment of my invention as shown in the accompanying drawmgs.

I claim: v

1. In a paper feeding machine, the combination with-suitable separating and feedin devices, and mechanism. for feeding a ban of sheets to said devices, of controlling mech anism normally active to prevent the operation of said bank feeding mechanism, a moving detector arm the arrest of which mechanism inactive and permits the operation of said bank feeding mechanism, and a fixed stop cooperating with said detector arm and so arranged that the en agement of the said. arm therewith is norma 1y prevented by a sheet.

- 2. In a paper feeding machine, the combinati n with suitable sheet combmg devices, and mechanism for feeding a bank of sheets to said devices, of controlling mechanism normally active to prevent the operation of entirely independent of said bank feeding mechanism, a moving de* tector arm the arrest of which renders said controlling mechanism inactive and permits the operation of said bank feeding mechanism, and a fixed stop cooperating with said detector arm and so arranged that the engagement of the said arm therewith is normally prevented by a sheet.

In a paper feedin machine, the combinationwith suitable sheet combing devices,

suitable sheet delivery mechanism and mech-- amsm for feeding a bank of sheets to said combing devices, of controlling mechanism normally active to prevent the operation of said bank feeding mechanism, a moving detector arm the arrest of which renders said controllin the operation of said bank feeding mechanism, and a fixed stop cooperating with said detector arm and so arranged that the engagement of the said arm therewith is normally prevented by a sheet.

4. In a paper feeding machine, the combination with separating and feeding devices, and bank feeding mechanism, of a stop arranged to be covered by a sheet when proper position, and controlling mechanism or said bank feeding mechanism, including a reciprocating detector arm arranged to be guided over said stop by the sheet and ar rested by said stop in the absence of a/sheet.

5. In a paper feeding machine, nation with a sheet support, se arating'and feeding devices, and bank fee ing mechan ism, of controlling mechanism adapted to tie termine the operation of said bank feeding mechanism, said controlling mechanism including a stop upon the sheet support, a detector arm mounted above the sheet sup port and movable back and forth thereover, and adapted to engage said stop in the absence of a sheet between them and be arrested thereby, and means controlled by said detector arm for permittingor Ipreventing the operation of said bank feeclng mechanism.

6. In a paper feeding machine, the c'ombination with a sheetsupport, separating and feeding devices operating above said support, and bank feeding mechanism, of a stop mechanism adapted to prevent the operation of said bank feeding mechanism, a stop shoulder formed in the sheet support beneath the plane of feed, a detector arm mounted above the sheet support and movable back and forth thereover and adapted to engage said stop shoulder in the absence of a sheet between them, and means controlled by said detector arm acting upon said stop mechanism to prevent the operation of said bank feeding mechanism.

7. In a paper feeding machine, the combination with a sheet support, separating and feedin devices operating above said support, and bank feeding mechanism, of a stop mechanism inactive and permitsceases mechanism normally in osition to permit the operation of said ban feeding mechanism, a stop shoulder formed in the sheet support beneath the plane of feed, a detector arm mounted above the sheet support and movable back and forth thereover and adapted to engage said stop shoulder in the absence of a sheet between them, and means controlled by said detector arm adapted to act upon said stop mechanism to move it into position to prevent the 0 eration of said bank feeding mechanism wien a sheet is in proper osition beneath said detector arm, and to e held against said action to permit the opleration of said bank feeding mechanism W en a sheet is absent from said position.

8. In a paper feeding machine, the combi- I nation with a sheet support, separating and feeding devices operating above said support, and bank feeding mechanism, of a lurality of stops arranged upon said s eet support and adapted to be covered by a sheet when in proper position, an adjustable detector arm movable back and forth over said stop and arranged to be guided thereover by a sheet, and controlling mechanism for sai bank feeding mechanism, detector arm.

9. In a paper feeding machine, the combination with a sheet support, separating and feeding devices operating above said support, and bank feeding mechanism, of a stop shoulder in said support arranged to be covered by a sheet, a detector arm mounted above the support, and adapted to engage and be arrested by said stop shoulder in the absence of a sheet, means for moving said detector arm back and forth over said stop shoulder, means for raising and lowering said detector arm with reference to the sheet support, and mechanism controlled by said detector arm for permitting or preventing the operation of the bank feed mechanism.

10. In a paper feeding machine, the combination with a sheet support, separating and feeding devices operating above said support, and bank feeding mechanism, of a stop shoulder in said support arranged to be cov ered by a sheet, a stop mechanism for preventing the operation of the bank feeding -1nechanism, a rock shaft for operating sai stop mechanism, and a detector arm mounted upon said rock shaft and movable back and forth over said stop shoulder and up and down with relation to said sheet suport. P 11. In a paper feeding machine, the combinationwith a sheet support, separating and feeding devices operating above said supcontrolled by said port, and bank feeding mechanism, of a stop shoulder in said support arranged to be covered by a sheet, a stop mechanism for said bank feeding mechanism, a rock shaft for operating said stop mechanism, a cam controlling the operation of said rock shaft, a rock arm mounted upon said rock shaft, a detector arm pivotall mounted upon said rock arm, and movab e back and forth and up and down with relation to said sto shoulder, and means controlling the up an down movement of said detector arm.

12. In a paper feeding machine, the combination with a sheet support, separating and feeding devices operating above said suport, mechanism including a pawl and ratchet for feeding a bank of sheets lapon said support to the separating and fee ing devices, an intermittently operating stop mechanism-for. preventing the operation of said pawl and ratchet mechanism, a stop shoulder in the sheet support, and a detector arm operating above the sheet support and adapted to engage said shoulder in the ab sence of a sheet between them, said detector arm controlling the operation of said stop mechanism.

13. Ina paper feeding machine, the combination with a sheet support, separating and feeding devices operating above said support, and bank feeding mechanism, of controlling mechanism for said bank feeding mechanism, including a rock shaft carrying a rock arm, a detector arm pivoted upon said rock arm and movable back and forth over said sheet support, a part projecting rearwardly from said detector arm and normally en aging a art projecting from the machine rame, an a stop shoulder upon the feeding support in the path of said detector arm, said stop shoulder being adapted to be covered by a sheet.

14. In a paper feeding machine, the combination with a sheet support, separatin and feeding devices, and bank feeding inec anism including a reciprocating pawl carrying member, a stop dog adapted to engage and prevent the motion of said awl carrying member, a rock arm adapte to operate. the normally inactive stop dog, cam mechanism for operating said rock arm, a detector arm controlling the operation of said rock arm, and a sto adapted to be covered by a sheet with WhlCh said detector arm is E. B. O. LIND UIsT.