US2272457A - Sheet feeder - Google Patents

Description

Feb. 10, 1942. A. BROADMEYER 2,272,457

SHEET FEEDER Filed June 25, 1940 3 Sheets-Sheet l Feb. 10, 1942.

A. BROADMEYER I 2,272,457

SHEET FEEDER 3 Sheets-Sheet 2 Filed June 25, 1940 Feb. 10, 1942. A. BROADMEYEER 2,222,457

SHEET FEEDER Filed June 25, 1940 5 Sheets-Sheet 3 Patented Feb. 10, 1942 ire TAT E S i TENT OFFEQE SHEET FEEDER Albert Broadmeyer, Norwalk, Conn, assignor to John McAdams & Sons, Incorporated, Norwalk,

Conn.

2 Claims.

This invention relates to sheet feeders of thetype wherein single sheets are fed successively from the top of a stack supported upon a vertically movable table, the sheets being moved from the stack to a conveyor by which they are carried to a point of delivery, which may be the feed end of a machine that performs some operation, as ruling, upon them.

Such feeders are well known and the presentinvention concerns certain improvements whereby superior operation and greater convenience is achieved.

One. object of the invention is to provide a novel arrangement for regulating the spacing of the successive sheets as they are delivered to" the conveyor, whereby any desirable spacing may be effected for sheets of any size.

Another object is to provide for a simple and positive adjustment for such a variable spacing means.

Still another object is the provision of a novel system for effecting the progressive elevation of the table that supports the stack of sheets to be fed.

A further object. is the provision of. a novel fe'eler-controlled intermittent device for effecting operation of the table-elevating mechanism as a stack of sheets on the table is depleted.

A still further object is the provision of a novel feeler-controlled system for elevating the table wherein no shock or force of operating parts can be transmitted to the feeler to cause it to dig into the paper.

Another object is the provision of novel feeler mounting and control system operated by a feel'er wherein adjustment of the feeler in directions of the motion of the sheets may be accomplished without changing the leverage of the feeler mounting.

In the accompanying drawings:

Figure 1 is a broken. side elevation of a feeder embodying the novel drive by means of. which the spacing of the sheets may be adjusted.

Figure 2 is a broken elevation of. the opposite or operators side of the feeder.

Figure 3 is a sectional view on line 3-3: of F ure 1.

Figure 4 is a detail side elevation of the intermittent drive for the table-elevating mechanism.

Figure 5 is a sectional view on line 5-5 of Figure 4.

Figure 6 is a top plan of the table-elevating mechanism, showing the intermittent drive and feeler mounting.

Figure 7 is a detail plan of the intermittent drive;

The feeder comprises a pair of transversely HI upon which the feeding spaced standards mechanism is-supported', and in therear of which is slidably mounted for vertical reciprocation a table" l2- upon which a stack of sheets maybe supported. Table l2 issupported on sprocket chains I3 that are trained over sprockets I4 mounted respectively on shafts [5 supported by bearings I So carried by the standards l0, the shafts l5 extending longitudinally in the directions of feeding.

The table I2 is counterbalanced by weights (not shown) which are attached to the free ends of the chains l3. Simultaneous rotation of the shafts i5 is accomplished by means of a transverse shaft it that drives the shafts [5 through gearing ll. Mechanism designated generally I8, which is controlled by' a f'eeler system, is provided for turning the shaft l6 according tothe depletion of a stack on the table, elevation of the" table being accomplished in a manner to maintain the top of the stack at a substantially constant level.

Feeding of the sheets from the top of a stack on the table is accomplished by a feeder device, preferable of the well known rotary suction wheel type (not shown) in a manner well known in the art. The feeder device is carried by a transverse shaft l9 journalled in suitable bearings in the standards In as is shown in Figure 6 as a suction wheel l9a. The sheets are fed forward in an edgewise direction from the stack to a conveyor' that comprises a plurality of tapes 20 that extend about a conveyor roller 2-! to a point of delivery. The roller 2| is mounted on a shaft 22 that acts as the main drive shaft of the machine, and to which power applied in any suitable manner;

The speed of the feeding depends upon the speed of rotation of the shaft I9, which drives the feeder device, and consequently the spacing of the sh ets upon the conveyor tapes 2!) de- J pends upon the relative speeds of the shafts l9 shaft 22 on a stub shaft 24 extending from the outside surface of the standard H) on the side of the machine away from the operators side, and such pulley 23' is driven by'the shaft 22 by gearing- 25. Pivotally mounted on the stub-shaft 24 for swinging motion about the center line of the pulley 23 is an arm 26 that carries at its distal end a pulley 2'1 driven by pulley 24 through a belt 28. Connected with the driven pulley 21, as by being an integral part thereof, i a driving pulley 29 that by means of a belt 30 turns a driven pulley 3| secured upon the shaft |9.

One of the paired pulleys 29 and 3| advantageously the driven pulley 3| as shown in Figure 3, is of variable effective diameter according to belt tension as of the type comprising two separate and relatively movable halves 32 and 33, one of which, here shown as 33, is fixed to the shaft, and the other being movable and urged towards the fixed half by a spring 24. By increasing the tension of the belt 30, the halves 32, 33 are forced apart, permittin the belt to ride towards the center of the pulley and decreasing its effective diameter, while by decreasing the tension of the belt the effective diameter of the pulley is increased. As the diameter of the other pulley remains constant, a change of belt tension results in a change of ratio of the diameters of the driving and driven pulleys, and consequently the speed of shaft l9, which governs the speed of the feeder device, with relation to that of the shaft 22, which governs the speed of the conveyor, may be governed by changing the distance between the pulleys 29 and 3|, which change alters the tension of the belt 35.

Change of the distance between the pulleys 29 and 3| is accomplished by swinging the arm 26, and the pulley 29 that it carries, about the center line of the pulley 23. As the arm swings concentrically about the pulley 23, tension of the belt 28 remains constant, but because of the eccentric movement of the pulley 29 with relation to the pulley 3|, such movement changes the dis tance between them.

As a convenient means of adjusting the position of the pulley 29 from the operator's station on the opposite side of the machine, a transverse shaft 36, extending across the machine, is mounted upon the standards it]. The shaft 35 is connected by a crank 31 and link 38 to the arm 26, so that rotation of the shaft swings the arm. A compression spring 39 is suitably mounted to counterbalance the arm. At the operators station a manual operating device 48 is arranged to turn the shaft 36 so that remote adjustment of the position of the pulley 29 may be readily accomplished.

Referring to the table-elevating mechanism, the shaft i6 is driven through a ratchet wheel 4| secured upon the shaft. Power to effect this drive is supplied from the main shaft 22 through a crank wheel 42 driven from the main shaft through gearing 43 (see Figure 2). A pitman 44 connected eccentrically to the crank wheel 42 constantly reciprocates a pawl carrier, designated generally 45, which is rotatably mounted on the shaft l5.

As best shown in Figures 4, 5 and 7, the pawl carrier 45 comprises a pair of body members 45 arranged on opposite sides of the ratchet wheel 4|, such members being provided with central bearings 41 through which the shaft l6 extends, and both members 45 extending forwardly and reaiwardly of the shaft It as arms 48 and 49 respectively. The end of the pitman 44 is connected with the pawl carrier 45 by a pivotal connection with a pin 59 extending between the rearward arms 49 of the carrier.

Between the forwardly extending arms 48, upon a pin 5|, is a swinging pawl 52 comprising a tooth arm 53 for engaging the teeth of the ratchet wheel 4|, an actuating arm 54 that extends forwardly of the pin 5|, and a detent arm 55 that extends downwardly from below the pin 5|. For cooperation with the detent arm 55 of the pawl, which is provided with a pointed end having inclined approaching surfaces 55, a plunger ball 57 is mounted in a bracket 58 that extends downwardly from one of the forwardly extending arms 48 of the pawl carrier and under the end of the detent arm 55. The plunger ball 51 is urged upward towards the pivot pin 5| by a spring 58, and its position is so related to the inclined surfaces of the detent arm 55, and the latter is so related to the tooth arm 53, that the point of the arm 55 passes the center line of the ball when the sharp tooth 55 of the arm 53 is slightly within the outer circumference of the ratchet wheel 4|. This arrangement is such that upon rearward motion of the pawl (clockwise as seen in Figure 4), the pawl tooth 59 in riding over a tooth of the wheel 4| will move the point of the arm 55 to the left of the center line of the ball 51, so that the pawl will be moved and held out of engagement with the wheel.

Movement of the pawl 52 to effect engagement of the tooth 59 with the wheel 4| when the wheel is to be driven is efiected by a vertically extending trip arm 65 that is pivoted between brackets 5| extending from the standard ii] for swinging along a plane at right angles to the planes along which the pawl carrier and pawl swing. The trip arm 60 has a trip member 62 at its upper end, a stop arm 63 adjacent its lower or pivoted end and extending in the same direction as the trip member 52, and an operating arm 84 adjacent its lower end and extending from the side opposite to the direction in which the arms 62 and 63 extend. The stop arm 63 is positioned between two adjustable stops 55 rigidly mounted on the bracket 6|, so that movement of the arm 55 in either direction may be limited.

The trip arm 60 effects engagement of the tooth 59 of the pawl 52 with the ratchet wheel 4| by being swung to such a position that the trip member 52 is placed in the path of the actuating arm 54 of the pawl, so that when the latter swings downwardly upon rearward motion of the pawl carrier (clockwise as seen in Figure 4) the member 52 of the trip arm will engage the arm 54 of the pawl and thereby swing the pawl upon the pivot pin 5| and move the tooth 53 into engagement with the ratchet wheel.

In order that the tooth 59 may be brought into engagement with the wheel 4| at the beginning of the forward stroke of the pawl carrier (counterclockwise as seen in Figure 4), when the trip member 52 has been positioned in the path of the actuating arm 54 of the pawl, and to provide relief for the pawl at the end of the rearward stroke after the member 62 has been engaged by the arm 54 prior to the end of the rearward stroke, a plunger 66 urged downwardly by a spring 61 is carried by the arm 54 and is so arranged that the end of the plunger 68 will engage the member 52 prior to the end of the rearward stroke, so that during completion of the stroke the arm 54 may continue to move downwardly while the plunger is held against motion, the spring 51 interposed between the arm 54 and the plunger 65 being compressed during this time. This permits the tooth 59 to ride over the teeth of the wheel 4| if necessary during the last part of the rearward stroke of the pawl carrier and assures that at the end of such rearward stroke the tooth 59 will be forced into engagement with the wheel 4 I, so that upon forward motion of the pawl carrier and pawl the wheel 4! will be driven by the pawl throughout such forward motion.

The position of the trip arm 60, and consequently the positioning :of the trip member 62 for engagement by the plunger 66, is controlled by a feeler that rests upon the top of a stack of sheets upon the table 12, in such fashion that when the stack is depleted and the feeler lowered the trip arm 60 is moved to place the member 82 in the path of the plunger 66, thereby efiecting engagement of the pawl with the wheel 4|, which results in driving the table-elevating mechanism to raise the table and restore the level of the top of the stack. The controlling system that accomplishes the movement of the trip arm is best shown in Figures 5 and 6.

A feeler am H! which has a slidable finger H mounted thereon extends laterally from a mounting 12 that is slidably adjustable along a shaft '13 that extends parallel to the sides of the table [2, in the direction of feed and is rotatably mounted on the standard [0. are rangement is contrary to usual practice wherein a feeler arm is mounted on a transverse shaft at the delivery end of the table. The end of the feeler finger H rests on the top sheet of the stack 14, and as the top of the stack is lowered due to the successive removal of sheets the finger falls, swinging the arm 76 and turning the shaft 13 in a direction that is clockwise as seen in Figure 5.

An operating arm 15 is secured to the forward end of the shaft 13 and extends past the standard 10 to a point at which its end is positioned for cooperation with the actuating arm 64 of the trip arm 60.

Referring to Figure 5, it will be seen that rotation of the shaft 13 in clockwise direction by the feeler arm Hi, resulting from lowering of the level of the top of the stack M, will raise the arm 15, swinging the trip arm 60 towards the path of the plunger 66. This swinging motion of the arm 60 continues until the plunger 56 is intercepted by the trip member 62, which causes the pawl to swing on the pawl carrier and effects engagement of the pawl with the ratchet wheel 41 as above described. Upon rearward -motion of the pawl and carrier, following a forward stroke during which the pawl has been in driving engagement with the ratchet wheel, the pawl is moved out of engagement with the ratchet wheel and held in disengaged position by the plunger ball 51, as above described. Whether the pawl will be again engaged with the ratchet wheel upon the next forward stroke or remain out of engagement, depends upon the position of the trip member 62 with relation to the path of the plunger 66, which position depends in turn upon the level of the top of a stack of sheets upon the table 12 with which the feeler finger is engaged.

By reason of the gearing ratios employed each ber 62 is moved through a relatively large arc upon a small movement of the feeler.

The arm 60 and its members 63 and 64 are so balanced that normally the arm swings to its It is further to be noted that the force of the descending plunger 66 when exerted upon the member 62 is transmitted to the arm Lit upon the same side of the pivot of such arm as the stop arm 63 projects from, which results in the resulting turning effort being finally exerted upon the lower stop 65. None of the force of the descending pawl carrier is transmitted back thnough the feeler system, which presents a material advantage over the prior practice wherein at each rotation of the constantly moving crank wheel commonly employed with a slotted link held out of operation by a feeler, an impulse was transmitted to the feeler, causing the latter to exert suificient pressure to dig into the stack and interfere with entirely accurate actuation of the table elevator.

In order to counterbalance the arm 15 and feeler arm Ill, and to adjust the pressure exerted upon the top of the stack by the feeler, the shaft 15 is provided with an arm." extending laterally of and moving with the shaft 13, so as to swing as the shaft is rotated. The arm 71 extends between an adjusting screw 18 and an oppositely disposed spring 19, both of which are supported by a bracket that extendsfro-m a journal bearing 8! that extends from the standard I0 and supports the shaft 13.

The feeder mechanism above set forth has many advantages. The provision of the readily adjustable variable speed drive from the main shaft, which drives the conveyor, to the feeder device permits an accurate adjustment of the spacing of sheets to be made while the machine is in operation. The spacing may be adjusted to the requirements of any particular job with great ease and may be accomplished irrespective of the size of the sheets being fed.

The arrangement of the table-elevating drive is such as to avoid wear on the parts, as ratcheting of the pawl tooth over the teeth of'the ratchet wheel is avoided. This also tremendously increases the silence of the machine in operation. All motions are rotary, which results in a minimum loss from friction and permits use of su-' perior bearings to avoid wear of the parts.

The arrangement of the system that controls the intermittent drive provides for great sensitivity to small changes in the level of the top of a stack, and the limited degree of'raising motion imparted to the table at each operation results in a very nearly constant level being maintained for feeding. All interacting parts are readily adjustable so that the mechanism may be easily set in condition for proper feeding operation.

From the foregoing it is thought that the construction, operation, and many advantages of the herein described invention will be apparent to those skilled in the art, and it will be readily appreciated that changes in the size, shape, proportions and minor details may be resorted to without departing from the spirit of the invention as set forth in the accompanying claims.

I claim:

1. In a sheet feeder including a conveyor that comprises a power shaft and a plurality of conveyor tapes that extend around the shaft and to a point of delivery, and a rotary feeder for successively feeding sheets to the conveyor from the top of a stack; a driving pulley rotated by the power shaft of the conveyor, a driven pulley arranged to rotate the feeder, intermediate driven and driving pulleys belted respectively to said driving and driven pulleys, said intermediate pulleys being mounted for rotation on a common center that is movable eccentrically about one and concentrically about the other of the first named pulleys, one of the pulleys that are relatively eccentric being arranged to vary in effective diameter according to the tension of the belt that connects it with the other such pulley.

2. In a sheet feeder including a conveyor that comprises a power shaft and a plurality of conveyor tapes that extend around the shaft and to a point of delivery, and a feeder operated by a rotary shaft extending parallel to and spaced from the power shaft for successively delivering sheets to the conveyor; variable speed driving means connecting the suction wheel shaft with the power shaft and comprising a driving pulley mounted adjacent and driven by the power shaft, an arm mounted for swinging motion about the center line of the pulley, a driven and a driving pulley journalled on said arm, said driven pulley being belted to the first mentioned pulley, a driven pulley secured upon the suction wheel shaft and belted to the driving pulley carried by the arm, said last mentioned belted pulleys being arranged to vary their ratio in accordance with the tension of the belt that connects them.

ALBERT BROADMEYER.

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