US2751224A - Sheet feeding arrangements - Google Patents

Description

.June 19, 1956 l. H. N. WATTON ET AL 2,751,224

SHEET EEEDING ARRANGEMENTS 3 Sheets-Sheet l Filed March 2'?, 1953 a/ NM/ ""Ill'llunhwll" Illlll.:

June 19, 1956 L. H. N. WATTON ETAL 2,751,224

SHEET FEEDING ARRANGEMENTS Filed March 27, 1953 3 Sheets-Sheet 2 Y #fro leys E June 19, 1956 L. H. N. WATToN ET Al. 2,751,224

SHEET FEEDING ARRANGEMENTS Filed March 27, 1955 3 Shets-Sheet 3 /n ver/fins hm@ Zar/#naaf SHEET FEEDING ARRANGEMENTS Leonard Herbert Neville Watton, New Malden, and Roland Brown and Frederick William Hall, London, Engiand, assignors to Hall Telephone Accessories Lim* ited, London, England, and Block & Anderson Limited, London, England, both British companies Application March 27, 1953, Serial No. 345,042 Claims priority, application Great Britain March 31, 1952 6 Claims. (Cl. 271-43) This invention relates to arrangements for feeding sheets (which term is to be understood to include also like articles such as envelopes) from a stack to a printing, duplicating or other sheet handling machine. The invention is concerned more particularly with arrangements whereby a table carrying a stack of sheets can be adjusted automatically so that the top sheet is at the correct level for being fed from the stack to the sheet handling machine.

According to the present invention, the feed table is pivotally mounted at or near the end remote from that at which the sheet is delivered and provision is made of means tending to urge the delivery end of the table in an upward direction, the upward movement being arrested by means controlled by a detector adapted to engage the surface of the uppermost sheet whereby the table is positioned with the said uppermost sheet at the desired level for being fed from the feed table.

Preferably, the front face of the stack of sheets is registered against a front plate extending downwardly from slightly below the feeding level and lying in a plane which is substantially tangential to the curved surface described by the delivery end of the feed table at the line of intersection of the feeding level with said curved surface. lf the sheets are stacked against the front plate when the delivery end of the feed table is in a depressed position, the sheets are progressively pressed back by a small amount as the feed table rises, thereby ensuring a constant position of the topmost sheet on the feeding level.

Conveniently, the motive power for lifting the table is provided by one or more springs which are tensioned by the act of depressing the table. To regulate the speed of rise of the table under the spring action a governor such as a pendulum-controlled escapement may be provided. The governor may be associated with the sheet detector in such manner that the table is locked not only when the top sheet is in the desired feeding level but also when the sheet detector is displaced out of its normal sheet-detecting position.

lf the sheets are fed from the table by a combing roller carried on a pivotal arm, this feed roller may also serve as sheet detector, the rising motion of the table being arrested when the feed roller is lifted a short distance by the table. The rising motion may also be arrested when the feed roller is pivoted away from the table into an idle position.

Instead of the motive power for lifting the table being derived from energy stored by the act of depressing the table into a loading position, the motive power may be derived from a moving part of the sheet handling machine, such as the printing drum of a hectographic copying machine, which may be electrically or manually operated.

More particularly when a combing roller is employed to feed the sheets from the feed table it is desirable to ensure that the feed action is suspended before the stack is exhausted, so that no damage results either to feed d 2,755 1,224 Patented `lune 19, 1956 ice roller or feed table. For this reason, it is advantageous to provide an adjustable trip which when the table reaches a predetermined position, prevents further operation of the machine. This can be done from a shaft geared to the lifting drive and adapted to trip the operation after the shaft has turned through a predetermined angle. In an electrically driven machine, the trip may be associated with the usual trip for interrupting the operation of the machine.

ln the accompanying drawings, which show a fragment of a duplicating machine in association with a sheetfeeding arrangement according to the invention,

Fig. l is a side view showing the feed table empty,

Fig. 2 is a corresponding view with the feed table loaded,

Fig. 3 is an enlarged side view of the escapement controlling the rising movement of the feed table,

Fig. 4 is an end view of Fig. 3,

Fig. 5 is a section substantially along the line V-V of Fig. 3, and

Fig. 6 shows a detail.

The side frames of the machine, one of which is indicated at 1, each carry a rearwardly extending arm (not shown), the rear ends of which are secured to a xed bracket 2 providing a pivot 3 on which are pivoted de pendent arms 4 rigidly secured to the sides of the feed table 5 at its rear end. The feed table 5, which is thus pivotally supported at 3, is provided in the usual Way with at least one side guide 6 which is adjustable laterally of the machine and is secured in position by a releasable locking lever 7. The sheets to be fed may be disposed between a pair of such side guides, each provided with a friction pad accommodated within a housing 8 on the side guide and bearing against the edges of the sheets with a pressure adjustable by a screw adjustment indicated at 9. Rigidly mounted on the side frames of the machine at the front end of the feed table 5 is a plate 10 having a downwardly extending portion 101.

The sheets positioned on the feed table 5 (see Fig. 2) are fed to the machine by means of a combing roller 11 which in its operative position rests on the top sheet and is driven to advance this sheet from the pile of sheets to the machine. The combing roller 11 is carried in an arm 12 pivotally mounted at 13. Means for driving such a combing roller to feed the top sheet to the machine are well known and consequently are not shown and will not be described.

The front end of the feed table 5 is supported from below by a roller 15 journalled at the end of one arm 14 of a bell crank lever which is secured on a shaft 16 and the other arm 17 of which is secured to a tension spring 18, the other end of which is anchored to the side frame 1 at 19. Preferably the bell-crank and spring arrangement is duplicated at the other side of the machine, so as to provide a symmetrical mechanism. lt will be apparent that when a pile of sheets is placed on the feed table 5 and the feed table is depressed at its front end to bring the top sheet to the level of the plate 10, the bell crank arm 14 is depressed and the arm 17 is moved away from the anchor 19 against the action of the spring 18. The spring 18 thus tends to urge the table 5 upwardly.

The escapement mechanism which is shown in greater detail in Figs. 3, 4 and 5 is provided to control the upward movement of the feed table 5 under the action of the spring 18. Secured on the shaft 16 (Figs. l and 2) is a gear wheel 20 meshing with a gear wheel 21 secured on a shaft 26 which carries a further gear wheel 22. The wheel 22 meshes with a gear wheel 23 fast on a shaft 27. Loose on the shaft 27 but coupled therewith by means of a uni-directional coupling such as a dog clutch is a further gear wheel 24. The wheel 24 meshes with a gear wheel 25 secured on a shaft 28 to which is also secured an escapement wheel 29. The rotation of the escapement wheel 29 is controlled by a rocker 30 to which is attached a pendulum arm 31 carrying a pendulum weight 32. When the pendulum 31,` 32 is free to swing, its natural frequency determines the rate of movement of the escapement wheel 29. The gear train 20-25 gives a predetermined step-down ratio and permits a correspondingly reduced rate of movement of the shaft 2,6 and thus determines the upward movement imparted to the table by bell crank 14 and roller 15. The unidirectional coupling between shaft 27 and gear wheel 24 permits the table 5 to be depressed by the operator for loading at any desired rate independent of the pendulum control.

To arrest the upward movement of the feed table 5 when the top sheet is at the appropriate level, means are provided for locking the escapement rocker 30. For this purpose, the rocker 30 carries an upwardly extending pin 33. This pin is adapted to be embraced by the free end of an arm 34 pivoted at 35 and controlled by a link 36. The link 36 is permitted to move lengthwise and is guided by a fixed pin 38 engaging in a slot 37. It will be apparent that when the link 36 is allowed to move downwardly, the arm 34 engages the pin 33 and holds the rocker 3ft. The link 36 is controlled by a detector responsive to the position of the top sheet of the pile. In the construction shown, this detector is constituted by the combing roller 11. An arm 40 secured to the pivotal arm 12 carrying the roller 11 is adapted to engage a pin 39 on the link 36, so that if the roller 11 drops below the level of the plate the arm 40 engages the pin 39 to lift the link 36 and with it the arm 34. The pin 33 is thereby released and the drive of the spring 18 is operative to raise the feed table 5 until the roller 11 is raised by the pile of sheets sutiiciently to allow the link 36 to drop to lock the escapement.

To facilitate the loading of the feed table, the arm 12 carrying the roller 11 is adapted to be raised into and latched in the position shown in Fig. l. For this purpose the arm 40 carries a star-shaped` latch 41 which normally slides over a part circular guide in a plate 42. The lower end of the guide terminates in a recess 43 in which the latch 41 engages to hold the arm 12 in the raised position. On lifting the arm 12 slightly from the raised position, the latch 41 is rotated clockwise from the position shown in Fig. l and it is then able to enter the circular part of the guide plate 42. The escapernent 30 is locked except when the roller 11 is in the desired sheet-feeding position.

As shown in Figs. l and 2, the downwardly extending part 101 of the plate 10 slopes away from the front end of the feed table S. Thus when the table 5 rises from its depressed position the pile of sheets is slightly displaced rearwardly in its movement over the plate 161, thus ensuring that slight irregularity in the stacking or positioning of the pile on the table S does not affect the position from which the feed of the top sheet commences. This pre-registration prior to the commencement of the feed movement facilitates the achievement of accurate registration in the subsequent feeding of the sheet.

if, when using a combing roller 11, as shown, it is desired to prevent the upward movement before the stack is exhausted, so that no damage results either to feed roller 11 or feed table 5, the shaft 16 may be provided with an adjustable trip which when the roller 1.5, and thus the table 5, reaches a predetermined position prevents further operation of the machine, i. e. when the shaft 16 has turned through a predetermined anglel from a position corresponding to maximum load position. If the machine is driven electrically, the trip may be associ. ated with conventional trip meansA for interrupting the operation of the machine. Such an arrangement is shown in Fig. 6 which represents a detail view on the opposite side of the machine to Figs. l and 2. In Fig. 6, the arm 44 secured on the shaft 16 carries a pin 45 which engages in a slot 46 in a link 47 the other end of which is pivotally connected to a lever 48 mounted on a pin 49 on the side frame of the machine. The lever 48 engages a trip member 56 adapted to release a clutch in the drive mechanism. Such trip-controlled clutch arrangements are well known in power-driven duplicating and like machines and consequently are neither shown nor described in the present specification. it will be apparent that the pin-and- slot arrangement 45, 46 forms a post-motion which permits the shaft 16 to perform a movement up to a predetermined setting before the trip is actuated. Adjustment may bc effected by altering the iength of the link 47 and/or providing an adjustable eccentric portion on the trip member 5i) for engagement with the lever 48.

We claim:

1. A sheet feeding arrangement comprising a feed table pivotally mounted at or near the end remote from that at which the feed sheet `is delivered, spring means tending to urge the delivery end of the table in an upward direction, a shaft on which said spring means acts tending to rotate said shaft, means associated with said shaft for lifting said table by the rotation under the spring action, an escapement wheel on a further shaft positively geared to said first shaft so as to rotate therewith, an oscillatory escapement member cooperating with said escapcment wheel and adapted to oscillate at a predetermined rate so as to regulate the rotation of said escapernent wheel and thereby to regulate the rate of rise of said feed table under the action of said spring means, a detector located in position to engage the surface of the uppermost sheet, and locking means controlled by said detector and operating on said escapement member to iock said escapement member to arrest the upward travel of the delivery end of the table when it is positioned with the uppermost sheet at the desired level for being fe from the feed table.

2. A sheet feeding arrangement as claimed in claim l, and in which the escapemcnt is a pendulum-controlled escapernent.

3. A sheet feeding arrangement as claimed in claim l, and in which the sheets are fed from the feed table by a combing roller carried by a pivotal arm and the combing roller is also utilised as the detector in that the angular movement of the pivotal arm is employed to control the locking means.

4. An arrangement according to claim l, and in which the spring means are constituted by a spring which is tensioned by the act of depressing the table.

5. An arrangement according to claim l and in which the front face of a stack of sheets is registered against a downwardly extending plate so disposed that if the sheets are stacked against the front plate when the deiivcry end .is in a depressed position the sheets are progressively pressed back as the feed table rises, substantially as and for the purpose hereinbefore set forth.

6. An arrangement according to claim 1, and in which means are provided to prevent further upward movement of the feed table at a predetermined position such that the stack of sheets on the table is not exhausted.

References Cited in the tile of this patent UNITED STATES PATENTS 218,355 Young Aug. 5, 1879 672,043 Sheckler Apr. 16, 1901 1,914,849 Davidson .Tune 2Q, 1933 1,960,482 Duncan May 29, 1934 1,989,911 Brasseur Feb. 5, 1935 2,167,477 Gluny July 25, 1939 2,472,441 Schmitt June 7, 1949

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