US2750804A - bergman - Google Patents

Description

June 19, 1956 c. vA. BERGMAN AUTOMATIC RAISING MECHANISM FOR FEED TRAYS Filed Nov. 15, 1952 5 Sheets-Sheet 1 YInn/entrena o'r A. Bergman by w WMS@ ATTORNEYS June 19, 1956 c. A. BERGMAN AUTOMATIC RAISING MECHANISM FOR FEED TRAYS 5 Sheets -Sheet 2 Filed Nov. 15l 1952 'NVENTO R l 'af] A. Bergman ATTORNEYS June 19, 1956 c. A. BERGMAN AUTOMATIC RAIsING MECHANISM FOR FEED TRAYs 5 Sheets-Sheet 3 Filed Nov. l5, 1952 FIG. 3.

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June 19, 1956 c. A. BERGMAN AUTOMATIC RAISING MECHANISM FOR FEED TRAYS 5 Sheets-Sheet 5 Filed NOV. l5, 1952 INVENTOR: Jar! A. Bergman ATTORNEYS Patented June 19, 1956 AUTOMATIC RAISING MECHANISM FOR FEED TRAYS Carl A. Bergman, Melrose, Mass., assignor to Standard Duplicating Machines Corporation, Everett, Mass., a corporation of Massachusetts Application November 15, 1952, Serial No. 320,771

4 Claims. (Cl. 74-169) This invention relates to feed trays of iluid duplicating machines and the like and more particularly to the pile of loose sheets on a feed tray with a platform which is maintained automatically at a constant level.

In fluid duplicating machines the top sheet of a pack of paper on the feed tray is fed between feed rolls which carry the sheet into printing contact with a master copy attached to a cylindrical drum. One function of the feed tray is to hold the supply of sheets so that the top sheet will always be at the proper uniform level to be fed to the feed rolls.

ln practice it has been found that common types of automatic feeding devices for duid duplicating machines can feed sheets continuously only from a small pack. lf the level of the feed tray is fixed the most sheets that can be fed from it Without readjustment is a pack less than an inch thick. The operator of the machine must be careful not to put too many sheets on the feed tray at one time or else the machine will not operate properly. if a great number of copies are to be made the machine must be stopped and the tray refilled frequently.

The feed tray of the present invention makes it possible to feed a greatly increased number of sheets successively without interruption, because the thickness of the pack is not a limitation on its capacity. The height of the feed tray is adjustable up or down to position the top sheet of the pack at the most etlicient feeding level, and as successive top sheets are fed into the duplicating machine this feed tray is raised automatically to maintain the top of the pile at the correct level. In practice the feed tray of this invention will support a full ream of hectograph copy sheets in the correct position for continuous feeding.

Devices have also been constructed having the same object in view, but, in general, they raise the feed tray the same amount for every cycle of the machine. Accordingly, they must be adjusted to correspond to the precise thickness of the paper being fed from the tray, otherwise the feed tray will be too high or too low after a few cycles of the machine.

The feed tray of the present invention will maintain a pack of sheets at the correct feeding level regardless of the thickness of the individual sheets being fed from the feed tray and no special adjustment is necessary. Even if sheets are mixed in one pile in varying thicknesses, for instance, varying from the thickness of card stock to that of onion skin, the feed tray will be maintained at the proper feeding level. This is particularly important in office work when it is desired to print letters and file cards successively.

The present invention will be understood by reference to the following detailed description and accompanying drawings in which the device is shown and described in connection with the essential parts of a uid duplicating machine, this being a convenient Way to illustrate the construction and mode of operation of the device. It

will beunderstood, however, that the device maybe usefully employed in connection with other machines in which sheets are fed one-by-one from the top of the pack.

Further objects and advantages will be apparent from the following description and accompanying drawings in which:

Fig. 1 is a side elevation partly cut away and partly in dotted lines illustrating the operation of this invention in conjunction with the drum and feed rolls of a uid duplicating machine.

Fig. 2 is a plan view partly cut away and partly in dotted lines showing the arrangement of the component parts of the feed tray of this invention.

Fig. 3 is a section along the lines 3 3 of Fig. 2, showing the operation of the manual lifting handle in dotted line.

Fig. 4 is a section on line 4 4 of Fig. 2.

Fig. 5 is a section on line 5-5 of Fig. 2.

Fig. 6 is an enlarged view of the left hand end of Fig. l partly cut away and partly in dotted lines showing the sensing device and indicating its operation.

Fig. 7 is a section on the line 7-7 of Fig. 4 indicating the position of the parts at the start of a lifting stroke.

Fig. 8 is a section through Fig. 7 showing the position of the lifting rings and the ball in cam grooves at the start of the lifting stroke.

Fig. 9 is a section similar to Fig. 7 but indicating the position of the parts at the climax of the lifting stroke.

Fig. l0 is a section through Fig. 9 showing the position of the lifting rings and a ball in one of the cam grooves at the climax of the lifting stroke.

Fig. l1 is a section on the line 1111 of Fig. 5.

Referring now to the drawings and particularly to Figs.

1 and 2, the feed tray A of this invention is mounted on the cabinet B of a fluid duplicating machine. A pack of sheets 10 to be printed by the fluid duplicating machine is placed on the platform 11 of the feed tray. The front of the pack rests against a forward stop 12 (see also Fig. 3) and one side rests against the side guide 13 which guides the sheets as they are moved forward.

A feed foot 14 of conventional type and arrangement has rubber rollers 1S resting on the top sheet of the pile of sheets 10, and is connected to a rod 16. The rod 16 is operatively connected to the drive mechanism of the fluid duplicating machine by any conventional means so as to cause the rod 16 to be reciprocated in timed relation to the operation of the fluid duplicating machine in a plane parallel to the feed tray at the side of the feed tray A. The drive'mechanism and the connection of the rod 16 to it are not shown since they may be of any well known type and arrangement.

As the feed foot 14 moves forward, 'the rubber roller 15 pushes the top sheet forward against a narrow flexible blade 17 which is adjacent one end of the forward stop 12. The sheet buckles up against the blade 17 until the front edge of the sheet snaps up over or slides over it. The feed foot 14 continues to push the top sheet forward up the guide 18 and into the bight of the feed rolls 19 and 20. These feed rolls then carry the sheet forward along the path indicated by the dash line and arrows 21 and are printed by passing between a pressure roll 22 and rotating drum 23 to Whicha master copy is secured. However, these `parts which feed the sheets from the pack 10 form no part of the present invention. They are shown and described for illustrative purposes and it is to be understood that any means for feeding the' sheets from a pack 10 on the tray A of this invention may'be'used without departing from the spirit of the invention.

As successive sheets are fed from the pack of sheets 10 a platform 11 is raised up by the lifting jack 24 from ,time to time as necessary to keep the pack at the correct level for proper feeding. The platform 11 is 3 moved up and down beside the side guide 13 and guide buttons 9 on the adjacent side of the platform 11 guide the platform and hold it in alignment with the side guide 13.

Referring to Figs. 1, 2 and 4 the body of the lifting jack 24 is attached to the bed plate 26 of the feed tray. The bed plate 26 is connected to and spaced apart from the cabinet B by wing nuts and bolts with intermediate spacing nuts as shown at 95 in Fig. 4, and a shaft 3i? projects out of the jack 24 and is attached to the underside of the platform 11. The upper end of the shaft 3i) is raised out of the body of the jack, which will be described subsequently. The lifting mechanism of the jack is actuated by movement of a jack lever 27., which is swingable about the top of the body of the jack A24 and which extends out beyond the left side of the feed tray underneath the bed plate 26. It swings in a short arc in a horizontal plane parallel to the bed plate 26 at the left side of the feed tray and is supported and guided betweenguide plates 93 and 94 under the bed plate 26.

The jack lever 27 is swung toward the rear of the tray to operate the jack 24 by the rearward movement of a linger 31 shown in Fig. l. The linger 31 is attached to and extends down from the rod 16, which as above described, reciprocates in timed relation with the dupli eating machine to operate the feed foot 14. An upturned edge 33 on the end of the jack lever 27 is in the path of movement of a rubber covered roller 32 on the bottom of the finger 31. When the finger 31 returns forward the jack lever 27 follows it forward under the tension of a spring 28. The spring 28 as indicated in Fig. 2 is attached between the jack lever 27 and the underside of the forward end of the bed plate 26. However, it is undesirable that the jack be thus operated on every stroke of the rod 16.

It is the function of a sensing device 25 to control the operation of the jack so as to operate only as required to raise and maintain the pile of paper on the platform 11 at the correct level for proper feeding. As shown most clearly in Fig. 6 the sensing device 25 consists of a rock i shaft 37 with two arms. One of the arms, a sensing arm 35, is in contact with the top of the pile of sheets 10. It is overbalanced forward so as to follow the level of the pack down as sheets are fed from the pack, and to rock the other arm, a stop arm 36, accordingly.

Looking at Figs. 2 and 4, the sensing arm 35 has a stud 38 attached at right angles to its upper end and projecting over the side guide 13. A roller 39 on the end of the stud 38 rests on top of the pack of sheets on the platform 1l.

The rock shaft 37 is mounted on bearings at right angles through the side guide 13. The sensing arm 35 is attached to the end of the rock shaft outside the side guide 13 and the stop arm 36 is attached to the rock shaft inside the side guide 13. As seen in Fig. 4 the bottom portion of the side guide is bent in at right angles and is attached to the bed plate 26. The rearward end of the stop arm 36 which has a stop plate 48 on its under side drops through the bent-in portion of the side guide 13, through an appropriate cut-out portion 132, Fig. 2.

When the pack of sheets is up to the correct level, the stop arm 36 is down with its stop plate 48, in the path of movement of the jack lever 27. This position of the stop plate 48 is indicated in dotted lines at 47 in Fig. 6. When the jack lever is pushed rearward it rides under and back beyond the stop plate 48. Then as the jack lever is pulled forward again, it is stopped against the edge of the stop plate 48 and held back. Thus the jack lever is prevented from being swung back and forth to operate the jack as long as the level of the pile is correct.

When the pack of sheets falls below the correct level, the sensing arm 35 follows the level down, swinging forward and down to rock the stop arm 36 up and lift 4 its stop plate 48 out of the path of the jack lever 27. The jack lever 27 is then free to operate the jack until the pack of sheets is raised to the correct level at which point the jack lever is again stopped as above.

Looking at Figs. 4 and 6, the sensing arm 35 is adjustably connected to shaft 37. The lower end of the sensing arm is rotatably mounted on the rock shaft and is adjacent a short arm 4Z which is rigidly fixed on the rock shaft. The position of the sensing arm 35 is adjustably fixed relative to the short arm 42 by a screw 4) through a slot 41 in the sensing arm and threaded into the short arm 42. Thus the sensing device may be finely adjusted with reference to the correct feeding level for the top of the pack of sheets 19. This adjustment is made when the machine is assembled and ordinarily need not be changed except as required when the worn parts are replaced.

The end of the stop arm 36 is connected to the rock shaft 37 by curling loosely around it as shown in Fig. 6. There is a slot 44 in this curled end of the stop arm 36. A screw 45 in the rock shaft 37 extends out through the slot 44. When the sensing arm rocks the rock shaft forward and down, the screw bears against the lower end of the slot 44 and rocks the stop arm up. By this arrangement downward movement of the sensing arm 35 raises Vthe stop arm 36 but upward movement of the sensing arm 35 will only drop the stop arm 36 to its lowest normal position and will not force it further down. Correspondingly the stop arm 36 may be pushed up with out forcing the sensing arm 35 down when the jack lever 27 rides under the stop face 4S of the stop arm. Furthen more, then sensing arm 35 may be pushed back up to a position indicated by the dash outline 46, Fig. 6, to be out of the way when a new pile of sheets lil is being put on the platform 11, With the sensing arm 35 in this position the stop arm 36 will remain in its lowest position indicated by dash line 47, Fig. 6. The screw 45 moves up in the slot 44 to the position indicated at 43.

Referring now to Fig. 5, the lifting jack 24 is encased in a housing 8. The lifting mechanism of the jack comprises a shaft 30 with one way ball and wedge ring clutches and 51 around it which prevent relative downward movement of the shaft 3() but allow it to move upward freely. These clutches 50 and 51 are rings with inside diameters slanted to form spaces which are V-shaped in cross-section between the rings and the shaft 3f). Sets of balls 53 and 54 are positioned respectively in these V-shaped spaces. When the shaft 30 is lifted these balls are rolled up toward the wider top part of the space where they roll freely. When the shaft 3i) is pushed down the balls wedge down in the narrower part, binding against the shaft and preventing its further downward movement.

The shaft 3i? is slidable in a sleeve made up of two sleeves and 56 joined in line by a threaded connecting sleeve 5'7.v The top of the sleeve 55 passes through a hole in the bed plate 26 of the feed tray and is fixed therein by the nuts 58 and 59 threaded on the sleeve 55. The sleeve 55 is of a slightly smaller bore than sleeve 56 so that a stop flange 6? on the end of the shaft 30 will pass freely up and down inside sleeve 56 but will not t through the sleeve 55. This allows sui'licient movement of the shaft 30 for the operation of the jack, but prevents the shaft 3ft from being pulled completely out of the sleeve S5 which would let the balls 53 and 54 fall out of position and render the jack inoperative. In the bottom of the sleeve 56 is a shock absorber for the bottom end of the shaft 2d. This shock absorber comprises rubber bumpers 61 topped by a disc 62 and held in the bottoni end of the bore of the sleeve by a plug 63 in the end of the sleeve 56.

The clutches 5@ and 51 encircle the outside of the sleeve 55. The sets of balls 53 and 54 in the clutches contact the shaft 3i) through two sets of holes, 64 and 65, in the wall of the sleeve 55. As shown in Fig. 1l each clutch has three balls and the corresponding holes are equally spaced around the sleeve 55 thereby positioning the balls to bear evenly against the shaft and act as bearings for the shaft. The holes 64 and 65 are slightly elongated vertically to allow the sets of balls 53 and 54 to move up and down as necessary for the clutching action.

The lifting action of the jack is accomplished by the operation of a pair of separating rings 66 and 67 which encircle the sleeve 55 below the clutch 50. As shown in Figs. 4, 7, 8, 9 and l0, these separating rings 66 and 67 each have three cam grooves 66a and 67a respectively, in their opposing faces. The cam grooves 66a in the top ring 66 slant from deep to shallow in a counterclockwise direction while the grooves in the lower ring 67 slant oppositely. Balls 68 are positioned between these rings in the opposing paired cam grooves. It will be observed that when the balls 68 rest in the deepest part of each opposed cam groove as shown in Fig. 8 the rings 66 and 67 will be close together and when they rest in the shallowest part the rings will be pushed apart.

A pin 70, Fig. 4, is fastened to the bed plate 26 and extends down to engage a notch 71 in the edge of the top ring 66 to prevent it from rotating. A pin 72 fastened to the jack lever 27 extends down into a notch 73 in the lower ring 67. As the jack lever is swung back from its forward position indicated in Fig. 7 to its rearward position shown in Fig. 9 the lower ring 67 which rests on a thrust ball bearing 69 is rotated counter-clockwise while the top ring 66 remains stationary. The balls 68 are rolled toward the shallow end of each opposed cam groove and the rings are pushed apart as shown in Fig. 10. The lower ring 67 is prevented from moving downward by the heavy coil spring 74 and snap ring 75 which supports the parts above it up in position and which is held up on the sleeve 56 by a washer. Therefore, as the rings 66 and 67 are pushed apart the top ring 66 is pushed up. it pushes the clutch 5i) above it up and the balls 53 in this clutch wedge against the shaft 30. The clutch 50 is thus locked to the shaft which moves up with the clutch to raise the platform 11.

When the jack handle 27 is returned back to its forward position the lower ring 67 is rotated clockwise. The upper ring 66 drops down toward the lower ring to the position in Fig. 8. The clutch 56 follows the upper ring 66 down and its grip on the shaft 30 is released. However, the shaft 3i) remains in a raised position, being supported by the clutching action of the clutch 51 which has not moved.

As seen in Fig. 5 the balls 53 are urged down into their clutching position by a ring 76 around the sleeve 55. The ring 76 is pressed down on the balls 53 by a light coil spring 77 between the ring 76 and the nut 59. The balls 54 are likewise urged to their clutching position by a ring 78 pressed down by a light coil spring 79. The spring 76 is located between the ring 78 and another ring 80 which is stopped against the underside of the clutch 50. A shield ring 81 surrounds the rings 79 and 80 and the spring '79 to shield them from interference with the separating rings 66 and 67 and the thrust ball bearing 69. The springs 77 and 79 are light so as to permit the balls 53 and 54 to be rolled out of their clutching position by relative upward movement of the shaft 30.

Still looking at Fig. 5, the jack lever 27 is swingable around a flanged collar 84 on the sleeve 55 between the nut 59 and the bed plate 26. The reduced portion between the flanges of the anged collar 84 fits a hole in the end of the jack lever 27. In the drawing the ange collar 84 is indicated as being formed by three adjacent washers the center washer having a smaller outside diameter than the other two.

The parts of the lifting mechanism of the jack 24 which encircle but are not attached to the sleeves 55' and 56 are held down in position by a coil spring 92 around the upper end of the sleeve 55. The coil spring 92 is seated under the flanged collar 84 and presses down on a washer 82, which in turn rests on top of the clutch 50. From the outer edge of the washer 82 two prongs 83 extend up' through holes in the bed plate 26 to a point slightly above the bed plate. This washer 82 and its prongs 83 are part of the means by which the shaft 30 is lowered as will be explained.

The heavy coil spring 74 is strong enough to support the movable parts resting on it, particularly the clutches 50 and 51 up in position. In addition it supports the weight of the loaded platform 11 whose weight is transmitted down to the spring 74 through the sets of clutch balls 53 and 54. To load all this weight onto the spring 74 there is a washer 85 on top of the spring 74. The washer 85 is stopped against the under edge of the connecting sleeve 57 and a stand-off ring 86 resting on a washer 85 by-passes the connecting sleeve 57 and presses up against the bottom of the clutch 51. To lower the shaft 36 and the platform 11 from a raised position a handle 87 of a lever 88 is pushed down. The lever 88 presses the prongs 83 of the washer 82 down thereby pressing the washer 82 and all the parts below it down against the tension of the spring 74. The clutches 50 and 51 are thus moved down relative to the sleeve 55 until the respective sets of balls 53 and 54 rest on the bottom edges of the holes 64 and 65. Then as the clutches move down a little more, the V-shaped space between the clutches and the shaft 30 drops from under the balls, leaving them supported up in the wide part of the V- shaped space. The normal gripping action of the clutches is prevented and the shaft 30 is free to sink down into sleeves 55 and 56. To stop the downward movement of the shaft 38 the handle 87 of the lever 88 is released, which allows the clutches to be pushed up to their normal clutching position by the spring 74.

As best seen in Fig. 2, the lever 88 extends under the platform 11 and over the prongs 83. The handle 87 of the lever 88 is fixed along its rearward edge. An end of the handle 87 is bent at right angles to extend out from under the platform 11 within easy reach of the operator of the fluid duplicating machine. The forward edge of the lever 88 is pivoted on the forward stop 12 as shown in Figs. 2 and 3 by ears 89 which are held through holes in the forward stop 12 by screws 90 in the ears. A spring 91 attached to the plate 88 and to the bed plate 26 pulls the lever 88 to the rear and holds the heads of the screws firmly against the forward stop to prevent rattling.

The platform 11 is also raised manually by lifting the handle 87 of the lever 88, as indicated in Fig. 3 by the dash lines 11a, 87a, and 88a. When the handle 87 is released the lever 88 drops to a normal position resting on the prongs 83 and the platform 11 remains up by the action of the clutches on the shaft 30. The lever 88 and its handle 87 are not heavy enough to depress the rongs 83 and release the clutches without being pushed own.

To prepare the feed tray A of this invention for operation, the sensing arm 35 is swung back to the rearward A,position shown in Fig. 6. A pile of sheets to be printed is set on the platform 11 against the forward stop 12 and the side guide 13. The platform is then raised or lowered by the handle 87 to set the level of the top of the pile up or down to be even with an edge 93 at the top of the side guide 13. This edge 93 is reduced below the rest of the top edge of the side guide 13 to mark the level at which the top of the pack of sheets 10 should be for correct feeding. Next the sensing arm 35 is swung to its forward position so that the roller 39 rests on top of the pack. Then the duplicating machine is started, and the sensing device 25 operates as previously described to permit the jack 24 to be operated or not, to maintain the top of the pack of sheets at the correct level.

There is a slight allowable variation in the level at which sheets will feed properly into the duplicating machine and this allowable variation is greater than the thickness of the thickest sheet that could be printed by V't7 the machine. In addition, the jack 24 is designed and built to raise the platform 11 an amount greater than the thickness of the thickest sheet that could be printed. The sensing device 25 is set toactuate the jack 24 when the level of the pack of sheets falls to a point slightly above the lower limit of the allowable level variation. Thus the jack will never raise the pack level too much or too little for correct feeding before the sensing device stops or starts the operation of the jack. In this way a diminishing pack of sheets is maintained at the correct feeding level no matter what the thickness of the sheets or even iE the pile is a mixture of sheets of various thicknesses.

I claim:

l, A lifting jack mechanism comprising in combination a sleeve, a load supporting shaft slidably received in said sleeve, two one-way clutches engaging the shaft through holes in the sleeve, said clutches comprising rings having slanted inside diameters around the sleeve `with balis spaced around the inside of the rings and normally supported through the holes in the sleeve between the slanted inside diameters of the rings and the shaft, a pair of adjacent separating rings around the sleeve between the clutch rings, means for reciprocally rotating one of said separating rings about the sleeve relatively to the other separating ring, said separating rings having respectiveiy oppositely slanted cam surfaces in their adjacent surfaces with balls positioned between them whereby the separating rings move apart and then together when one is reciprocally rotated relatively to the other, a spring supporting said clutch rings and separating rings in position longitudinal-ly of said sleeve, said spring being at least strong enough to support the clutches, the separating rings and said shaft, and means to move said clutches along the sleeve against the tension of said spring until the distance between the slanted inside diameters of the clutch rings and the shaft at said holes through the Sleeve is greater than the diameter of the halls which are through said holes.

2. A lifting jack mechanism comprising in combination a base, a load supporting shaft longitudinally movable vertically relative to the base, a first one way clutch connected to the base and longitudinally engaging the shaft normally preventing downward movement of the shaft while allowing upward movement relative to the base, a second one way clutch above yand movable vertically relative to the first said clutch and longitudinally engaging the shaft when moved upwardly away from the rst said clutch and releasing the shaft when moved downwardly to ward said rst clutch, means to reciprocate said second clutch relative to said first clutch to raise the shaft including a pair of relatively rotatable cam elements surrounding said shaft between and abutting said clutches,

First said clement being fixed against rotation and a second said element being arranged with respect to said first element to move said elements apart and together when said second element is reciprocally rotated relative to said first element, and an operating lever connected to said second eement and reciprocally pivotally movable in a plane normal to the axis of said shaft.

3. In the combination as set forth in claim 2, means simultaneously to release the normal engagement of said clutches with said shaft thereby allowing downward retraction of said shaft relative to the hase.

'i. In the combination as set forth in claim 2, said cani elements comprising a pair of adjacent rings mounted concentric 'to the axis of said shaft, said rings having circular oppositely registering cam grooves in their adjacent faces, said grooves being respectively deep and shallow at corresponding ends and a ball bearing riding in said grooves, said ball rolling into the shallow ends of the grooves to force the rings apart and into the deep ends of the grooves to allow the rings to come together in accordance with relative rotation of the rings in opposite directions.

References Cited in the lile of this patent UNITED STATES PATENTS 383,709 Crecelius May 29, 1888 824,963 Trewhella July 3, 1906 1,989,911 Brasseur Feb. 5, 1935 2,032,166 Breuer Feb. 25, 1936 2,167,477 Glunz July 25, 1939 2,539,090 Leland Jan. 23, 1951

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