US2774595A - Apparatus for separating stacked flat articles - Google Patents

Description

Dec. 18, 1956 v H. E. J. BUTLER 2,774,595

APPARATUS FOR SEPARATING STACKED FLAT ARTICLES Filed July 15, 1952 2 Sheets-Sheet l Dec. 18, 1956 H. E. J. BUTLER 2,774,595

APPARATUS F OR SEPARATING STACKED FLAT ARTICLES Filed July 15,.1952 2 Sheets-Sheet 2 r, Cr

pulleys 7a.

APPARATUS For: SEPARATING STACKED FLAT ARTICLES Hugh Ernest James Butler, Harrow, England, assignor to HallTelephone Accessories Limited, London, England,

a British company V Application July 15, 1952, Serial No. 298,908

priority, application Great Britain July 24, 1951 i 3 claim. (c1; z71 12 This invention relates to apparatus for separating stacked flat articles and is particularly although not exclusively concerned with apparatus for separating postal letters one by one from a stack or pile of letters.

In the mechanized sorting of postal letters it is desirable that letters fromv a stack to be sorted shall be separated individually at'time intervals determined by the rate of sorting and fed to a. sorter who should be able to start or stop the supply of separated letters at will.

According to the present invention, an apparatus for separating stacked flat articles, such as letters, includes a conveying unit for transferring the articles one at a time from a position in an inclined or approximately horizontal plane to another position in an approximately vertical plane. a

The invention and its subsidiary features will be fully understood from the following more detailed description of an example of a construction according to the invention, reference being made to the drawings accompanying this specification, in which:

Fig. l is an isometric projection, and

Fig. 2 is an end view.

p The apparatus shown in the drawings comprises a postcard or buckling attachment for ensuring positive separation of the individual articles, a curved or suitably inclined and slotted guide having flexible belts projecting through slots in the guide to form a conveyor for changing the direction of the path of'the letter, a defleeting plate in an approximately vertical plane to receive and deflect the letters or articles into an approximately vertical position, and a horizontal gate to support the letters above a moving belt so that the instant at which the letter is allowed to drop to the conveyor may be controlled.

The postcard or buckling attachment comprises two domed pads or stops 1 attached to adjustable arms which can be clamped by knurled nuts 2 to a mounting frame 3, the mounting frame being clamped by knurled nuts 4 to the main base or framework of the apparatus near a pick up head 5 of the type adapted to pick up the letters or articles by suction provided from a suitable source of low pressure (not shown). The required position of the domed pads is obtained by adjusting the arms which can be raised and rotated. General positional adjustment can also be obtained by moving the mounting frame so that the arms are moved towards or Y away from the pick up head.

the rear of the mechanism between front and rear guides 11 and 12 and immediately above a horizontal conveyor or traversing belt 15 (partly illustrated). The upper part of the plate 12 extends in an approximately vertical plane as shown and forms a deflecting plate for deflecting the letters or articles into an approximately vertical position.

The head 5 is controlled by a known mechanism by which it is caused to lift each letter or article to a rest position in which the article is separated from the stack and then to move the letter or article towards the guide ,6.

has openings toallow flexible belts 7 to project through.

The flexible belts are mounted on and are driven by The belts are in contact'with resiliently mounted rollers 8 so arranged in the main base or framework as to be displaceable radially of their paths of rotation (see Fig. 2). The guide 6 is curved to follow the contour of the belts when in contact with the rollers 8. Serrated or toothed wheels 9 are mounted on the upper shaft carrying the belts.

A'horizontal gate 10, solenoid operated, is housed at A stack of letters or flat articles is placed in a vertical or an oblique container below the pick up head 5. The suction head, in the rest position, holds a letter with the outer edges in contact with the domed pads 1 so that the letter becomes curved. The degree of curvature can be varied by adjusting the vertical position of the pads. Should more than one letter be picked up at a time, the action of curving them introduces movements between the lower surface of one and the upper surface of the next. This movement causes the items to separate, the lower item falling back on to the top of the stack.

From the rest position the letter is carried by the suctionhead 5, towards the guide 6. The leading edge of the letter hits the guide 6, and any letters which have rotated on the head or were not straight in the stack are re-aligned squarely with the direction of movement.

The suction head Scarries the letter forward until the leading edge is placed between the rubber belts and the' sprung rollers 8. vThe head 5 then moves away to pick up another. letter and to return to its position of rest with the next letter raised above the stack. The belts, being in motion, carry the letter under the rollers 8.. The movement of the rollers 8 can be used to indicate the stiffness, thickness and curvature of the letters by means of an attachment (not shown) designed to respond to the movement of the mounting. For example, the

sprung rollers may be provided with an associated switch vertical position. 'The trailing edge of the letters 13,

14 (indicated in dot and dash lines) drops into a tooth space on the wheels 9 and is carried by the latter past and over the end of the belt. The letter then drops between the front and the rear guides 11 and 12 and is arrested by the horizontal gate 10. The operation of the gate 10 is co-ordinated with the movements of the suction pick up 5 for controlling the delivery of the letters one at a time as required by the sorter. It is to be observed that the gate 10 is disposed only a short distance above the level of the horizontal conveyor or traversing belt 15 so that each letter drops a minimum distance on to the horizontal traversing belt. Letters are thus less likely to topple as new motion is imparted to them by the horizontal traversing belt.

It will be understood that although particular forms of construction of the various compound parts of the apparatus have been described modifications and alternative constructions within the scope of the invention may be adopted. Thus any suitable means of conveying the letters one at a time may be employed, and said conveying means may be controlled by photo electric device top of a stack of such articles, comprising a base, support means on said base for retaining said articles in stacked relation, suction means disposed on said base for movement along a path, located above and substantially centrally of said stack, said suction, means, when at one portion of said path of movement thereof and connected to a source of low pressure, being disposed above said support means for engaging the central portion of the uppermost article so as to draw, raise and remove said article from said stack, a pair of arms carried by said base and located, respectively, above said support means and spacedfrom said suction means on opposite sides of said one portion of said path of movement of the latter, a stop on each of said arms for engagement with the lateral portions of said article, means on said base for adjusting said arms toward and away from said support means, respectively, said arms with said stops normally extending further toward said support means and said stack than said suction means, with said stops being vertically spaced from said; top of said stack, whereby said article, upon being rasied by said suction means, abuts with its lateral portions against said stops and is centrally buckled upwardly while being removed from said stack but again becomes fiat upon movement of said suction means along said path and away from said stops, a first guide located on said base and adjacent another portion of said path of movement of said suction means, said first guide being arranged at an upward slant relative to said base and said path and intersecting the latter so as to engage the leading edge of said article upon arrival of said suction means at said other portion of said path of movement, thereby guiding said article upwardly, said first guide being provided with a pair of spaced parallel slots extending therethrough in the direction of movement of said article therealong, said slots being substantially aligned with said stops, a pair of spaced, parallel shafts rotably supported on said base adjacent the ends of said slots, respectively, a pair of endless flexible belts supported on said shafts for movement in respective endless paths, corresponding portions of said belts extending through said slots for movement along the article-engaging part of said first guide, a third shaft mounted on said base and above said first guide, a pair of friction rollers rotatably mounted on said third shaft and opposite said slots, said rollers being in peripheral engagement with said belts, respectively, means operatively connected to at least one of said shafts for driving said belts along said endless paths, whereby said article, upon release from said suction means due to disconnection of the latter from said source of low pressure, will have, said lateral, portions thereof entrained between said rollers and said belts for movement along said first guide and with said central portion of said, article out of contact with said rollers and belts, and a second, substantially vertical guide on said base and adjacent the end of said first guide remote from said suction means for receiving said article in flat condition from said first guide, and providing a. drop path for said article toward a conveyer belt when the latter is located beneath said second guide.

2. Apparatus according, to claim 1,, further comprising means mounting said, third shaft. for movement toward and away from said belts, respectively, whereby the,

positions of said rollers relative to said belts will. be automatically varied in accordance with, the, stiffness of said article.

3. Apparatus according to claim 1,. further comprising a pair of toothed wheels mounted on onev of said beltsupporting shafts adjacent said second guide and the upper end of said first guide, said wheels being rotatable with said last-named shaft, whereby the trailing edge of said article is received in the space between apair of teeth of each of said wheels and transferred by the, latter to said second guide from said first guide.

References Cited in the file of this patent UNlTED STATES PATENTS 700,722 Appel May 27, 1902 958,230 Cowley May 17, 1910 1,060,943 Rehack May 6, 1913 1,309,544 Pritchard July 8, 1919 1,743,158 Morse 1311.. 1.4, 1930 1,755,662 Petersen Apr. 22, 1930 2,105,068 Allendorf Jan. 11, 1938 2,125,199 Rheutan July 26, 1938 2,231,339 Krueger Feb. 11,, 1941 2,282,224, Harrold May 5, 1942

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