US2950675A

US2950675A - Apparatus for mechanically handling thin flat articles

Info

Publication number: US2950675A
Application number: US733076A
Authority: US
Inventors: Copping Geoffrey Perey; Parker Donald James; Barr David John
Original assignee: Post Office
Current assignee: Post Office
Priority date: 1957-05-10
Filing date: 1958-05-05
Publication date: 1960-08-30
Anticipated expiration: 1977-08-30
Also published as: GB854863A; DE1145553B; FR1206767A; BE567587A; CH366058A

Description

Aug. 30, 1960 G. P. COPPING ET AL 2,950,675

APPARATUS FOR MECHANICALLY HANDLING THIN FLAT ARTICLES Filed May 5, 1958 5 Sheets-Sheet 1 Miami;

[i 6 60FFIPE i? (OPP/17c,

.Do/YfiLp f P ER DAV/D I BA R, v

1960 G. P. COPPING ETAL 2,

APPARATUS FOR MECHANICALLYHANDLING THIN FLAT. ARTICLES Filed May 5, 1958 5 Sheets-Sheet 2 .ZDAV/D f BARR, ,5; 704

Aug. 30, 1960 ca. P. COPPING ETAL 2,950,675

APPARATUS FOR MECHANICALLY HANDLING THIN FLAT ARTICLES Filed May 5, 1958 5 Sheets-Sheet 3 DVcfifa/q GEOFFREY P LQPP/A Dor /up I PAR .D i W0 JT BA RR,

Aug. 30, 1960 I copp ETAL 2,950,675

APPARATUS FOR MECHANICALLY HANDLING THIN FLAT ARTICLES Aug. 30, 1960 G. P. COPPING ETAL APPARATUS FOR MECHANICALLY HANDLING THIN FLAT ARTICLES Filed May 5, 1958 5 Sheets-Sheet 5 Patented Aug. 30, 1960 lice APPARATUS FOR MECHANICALLY HANDLING THIN FLAT ARTICLES Geoffrey Percy Cupping, Chesham, Donald James Parker,

Rickmansworth, and David John Barr, Pinner, England, assignors to Her Majestys Postmaster Gcnerai, London, England Filed May 5, 1958, Ser. No. 733,076

Claims priority, appiication Great Britain May 10, 1957 3 Claims. (1. 101-436) The present invention relates to apparatus for mechanically handling thin flat articles, and has for an object to provide improved apparatus for feeding thin flat articles sucessively from a stack of such articles, and improved apparatus for forming a stack of thin flat articles from a stream of the articles fed thereto.

It is a further object of the invention to provide improved apparatus for handling letter mail and including means for feeding letter successively from a stack of letters, means for effecting a stamp cancellation operation on each letter fed from the stack and means for reforming the letters after stamp cancellation into a fresh stack of letters.

In apparatus for feeding thin fiat articles, such as for example letter mail, from a stack thereof, it has heretofore been customary to feed the articles horizontally from a stack of the articles supported vertically on edge, by means of a drive-out roller frictionally engaging the foremost article of thestack and to restrain adjacent articles from issuing with the foremost article by means of a reverse roller frictionally engaging the rear surface of such adjacent articles to oppose their movement out of the stack and thereby tend to drive them back into the stack.

In such known apparatus the peripheral surface of the reverse roller is opposed to but spaced from the peripheral surface of the drive roller, and in the case of letter mail-where items vary widely in shape and size and where a high operating rate is required-the known ap paratus is reasonably efiective but requires experienced manual control of the feeding of the stack in order to achieve a high output rate. This manual control is necessary in order to maintain a light contact pressure between the drive-out roller and the foremost article of the stack thereby to reduce the possibility of two articles being fed from the stack simultaneously. Furthermore, the variation in thickness and of the coeflicient of fric tion between adjacent items of letter mail render it impossible to drive the stack forward continuously, either by positive drive means or under the action of a spring, and it becomes essential that the stack be fed manually by an operator so that the feed pressure on the stack can be varied according to the characteristics of the foremost item engaged by the drive-out roller and thereby to ensure that only the foremost article is fed out from the stack.

According to the present invention apparatus for feeding thin fiat articles successively from a stack of such articles supported on edge on a stacking floor and urged in one direction along the floor, comprises a drive-out means including a moving surface for frictionally engaging the front surface of the foremost article of the stack to feed it outwardly transversely of the stack and means for frictionally engaging the rear surface of the article to cause a restraining force to be exerted against said outward movement, the said rear surface engaging means co operating with the said moving surface to exert pressure on an article engaged therebetween so that the article is bowed transversely to the direction of movement thereof.

Thus, the presure exerted on an article engaged between the moving surface and the retraining means is related to the stiffness of the article. If, therefore, the moving surface and the restraining means are relatively disposed so that when a single article is engaged therebetween the impelling force exerted by the moving surface is much greater than the force exerted by the restraining means, then if two articles issue simultaneously from the stack the increased stifiness of the two superposed articles will result in a considerable increase in the force exerted by the restraining means so that while the foremost article is fed out from the stack by the moving surface the rear article is restrained against such movement by the restraining means.

In one arrangement of drive-out means according to the invention, the said moving surface is provided by the peripheral surface of a drive-out roller frictionally engaging the front surface of the foremost article and the said restraining means comprises a pair of reverse rollers rotating in the. opposite direction to the drive-out roller and engaging with their peripheral surfaces the rear surface of the article, the respective peripheral surfaces of the reverse rollers being laterally displaced to either side of the peripheral surface of the drive-out roller and slightly inwardly thereon in the direction of the axis of the drive-out roller so that when an article is engaged between the drive-out roller and the reverse rollers it is caused to flex transversely to the direction of movement.

In an alternative arrangement of drive-out means the moving surface is provided by a drive-off belt supported upon rollers and continuously driven to provide the required moving surface for frictionally engaging the foremost article of the stack.

As a further alternative arrangement of drive-out means, the restraining means may be provided by stationary surfaces frictionally engaging the rear surface of the article and co-operating with the moving surface to produce transverse bowing of the article while opposing movement of the article by the said moving surface.

The articles are usually fed singly from the stack for the purpose of performing a further operation on each article, for example, in the case of letter mail, for stamp cancelling, and after such further operation it is required to restack the articles.

According to a further feature of the invention, therefore, there is provided apparatus for stacking thin flat articles successively fed thereto in a stream of articles spaced one from another in the direction of feed, the said apparatus comprising a drive means for positively feeding each article downwardly into the apparatus and towards a stacking device positioned beneath the said drive means, further article engaging drive means positioned in the path of the article intermediate the first drive means and the stacking device, an article-controlled means for effecting intermittent operation of said second steps the leading portion of one article fed into the ap-- paratus by said first drive means is caused to lie against the trailing portion of the immediately preceding article which has advanced one step through the second drive means, so that the articles are fed by the second drive means to the stacking device in overlapping or tiled relation.

According to a still further feature of the invention the said second drive means comprises a pair of driven rollers into the bite of which the articles are fed, one of said rollers being adapted to print a legend or other inscription on to the leading portion of each article as the tiled articles are fed by the rollers to the stacking device.

fed to the second drive means so that the leading portion of each item carries the stamp or stamps in position to be engaged by. the cancelling roller. In thisfmanner the apparatus functions as a combined letter cancelling and stacking machine. v r

The invention will now be described with reference to the accompanying drawings, in which:

Figure l is a diagrammatic representation of one form of apparatus according to the invention for feeding items of letter mail from a stack of lettermail;

Figure 2 is a section taken along the linejIL- IIof Figure 1 and showing in' exaggerated form the overlapping of the drive-out and reverse rollers;

Figure 3 is a diagrammaticrepresentation of a combined letter cancelling and stacking apparatus according to the invention; a

Figure 4 is a perspective exploded view of a specific construction of letter-feeding'apparatus according to the invention;

' Figure 5 is a plan view of a construction of stacking box for use in the apparatus diagrammatically shown in Figure 3; and

Figure 6 is 'a section taken along the lines VL-VI of Figure 5. V v

Referring firstly to Figure '1 the apparatus shown therein comprises a stacking floor 1 for supporting on edge a stack of letters 2, the floor '1 inclining downwardly towards a front end wall 3 and being spaced therefrom as at 4 to provide a gap through which the foremost letter of the stack is fed to a drive-out roller 5 having a tyre 6 of a resilient material'the periphery of which provides a moving surface frictionally engaging the front face of the letter to drive the letter downwardly. In order to assist the action of gravity in feeding the foremost letter to the drive-out roller 5 a further drive-out roller 7-- similar to the roller 5is positioned above the level' of 'the floor .1 and extending through an aperture in the wall 3 to engage the front face of the foremost letter.

A pair of reverse rollers '8 is Supported at the upper end of an arm 9 pivoted as at 10 for swinging movement towards and away from the drive-out roller 5, the reverse rollers 8 being spaced upon a common drive shaft 11 so that the respective peripheral surfaces of the reverse rollers 8 are positioned at either side of the peripheral surface of the drive-out roller 5, as will be clearly seen from Figure 2. The reverse rollers frictionally engage the rear surface of letters fed downwardly by the drive-out roller and are preferably provided with a hard tyre so that when a letter is engaged between the drive-out roller and the reverse rollers the frictional drive of the resilient tyre of the drive-out roller is greater than the reverse drive due to the frictional engagement of the hard tyre of the reverse rollers. V

The pivoted arm 9 is spring loaded towards the driveout roller 5 by means of a compression spring 12, and an adjustable stop -13 limits the movement of the arm towards the drive-out roller. As will be seen from Figure 2 the stop 13 is adjusted so that the respective peripheral surfaces of the drive-out rollers 8 are displaced slightly inwardly thereof in the direction of the axis of the driveout roller and it will be apparent that a letter engaged caused by the bowing of the letter is not sufiicient to cause the reverse rollers seriously to impede the operation of the drive-out roller, but when two letters issue from the stack and are engaged simultaneously between the drive-out and reverse rollers the combined stiffness of the two letters due to the bowing of the letters gives rise to a high contact pressure between the reverse rollers and the rear face of the second letter" and the reverse rollers restrain the second letter from being fed downwardly with the first letter.

In addition to inclining downwardly towards the front end wall 3 the stacking floor 1 is also inclined in the transverse direction so that the. letters 2 are supported along one side edge by a sidewall (not shown). In this manner the stack of letters is securely supported and the stack is urged by gravity towards the front wall 3. In order .to assist the feeding action of the stack a smooth light metal roller 16 may be positioned in engagement with the rearmost letter of the stack.

Referring now to Figure 3, there is shown a combined stamp cancelling and letter stacking apparatus to which, for example, the letters-fed from the stack 2 by the apparatus of Figure 1 may be delivered. The apparatus of Figure 3 comprises a first pair of drive rollers 17 for receiving a letter delivered thereto and for driving the letter downwardly into the apparatus between a vertical guide wall 18 and a downwardly inclined guide wall 19 so that the leading edge of the letter impinges upon the guide wall 19 and is deflected thereby into the bite of a second pair of feed rollers 20.

The first feed rollers 17 are continuously driven but the second pair of rollers 20 is adapted to be driven intermittently in response to each letter as it is fed to the rollers 17. 'For this purpose each letter prior to entering between the first feed rollers 17 is caused to intercept a beam of light 21 focused upon a photo-electric cell 22 which controls an electric circuit for energising a single revolution clutch (not shown) which is geared to the rollers 20 through an epicyclic gear train adapted to rotate the rollers 20 so that they accelerate smoothly to a maximum peripheral speed and then decelerate smoothly to rest. From the second feed rollers 20 the letters are delivered in a manner hereinafter described to a stacking box comprising a downwardly inclined fioor 23, a movable back-rest 24 and a rotating star-wheel 25 extending through an aperture 26 in a front wall 27 to stack the letters against the back-rest 24. The stacking box and back-rest 24 are shown purely diagrammatically in Figure 3 and a construction of stacking box suitable for use in the apparatus of Figure 3 will hereinafter be more fully described with reference to Figures 5 and 6.

In operation of the apparatus shown in Figure 3, a letter arriving at the upper feed rollers 17 intercepts the light beam 21 and the photo-electric cell 22 energises the clutch to impart a single revolution to the rollers 20. A delay circuit is included between the photo-electric cell and the clutch operating circuit so that the clutch engages when the leading edge of the letter is a predetermined distance above the rollers 20 in order that when the leading edge of the letter is engaged by the rollers 20 they are moving with a peripheral speed substantially equal to the linear speed of the letter. In this manner the letter is brought smoothly to rest between the rollers 20 after moving forward a distance equal to one half of the circumference of the rollers. It will be understood that the line joining the axes of the rollers 20 is inclined with respect to the horizontal so that when a letter is gripped by the rollers the rear of the letter is swung sideways against the inclined guide wall 19 to ensure that the succeeding letter delivered by the feed rollers 17 will impinge upon the right-hand surfaceas seen in Figure 3of the letter already engaged by the rollers 20. Upon the entry of said succeeding letter the rollers 20 are again rotated after a predetermined delay, as previously described, and the letter already engaged between the rollers, and the leading portion of the next letter, are together fed through the rollers 20 a further step. As each letter when engaged between the rollers 29 is swung sideways against the guide wall 19 the succession of letters will always overlap in the same direction and are thus in suitable condition for stacking, and furthermore and providing the letters are fed so that the stamp or stamps are on the leading end of the letter, the right-hand roller 20 may take the form of a cancelling roller, since due to the overlapping relation of the letters the cancelling roller only engages the leading portion of each letter.

The operation of the apparatus will be clearly understood from the relative positioning of the letters in Figure 3 in which there is shown at 28 the stack of letters formed by the apparatus, at 29 a letter which has already been advanced one step through the apparatus, at 30 a letter partly advanced one step and upon which one half of the printing surface of the cancellation roller has engaged, and at 31 a letter having intercepted the light beam 21 and being driven downwardly by the feed rollers 17.

A predetermined time after the letter 31 intercepts the light beam 21, i.e. when the letter occupies a position approximately as shown in the figure, the rollers 20 will rotate and drive the letter 29 into the stacking device and the letter 30 a further step through the rollers 29 to complete the printing of the cancellation thereon, While the letter 31 superposed upon the trailing end of the letter 30 will be engaged by the rollers 20 to occupy a position similar to that of the letter 31), when the rollers have completed one revolution.

Referring now to Figure 4 of the drawings, there is shown in perspective exploded view one specific construction of letter feeding apparatus in which a stack support in the form of an L-section support tray or trough comprises a floor 32 along one side edge of which is a vertically extending wall 33. Both the floor 32 and the wall 33 are formed by a plurality of spaced elongated rollers 34 rotatably supported in end plates 35, there being provided suitable drive means (not shown) for rotating the rollers simultaneously, the rollers of the floor 32 being rotated anticlockwise as viewed in Figure 4 and the rollers of the wall 33 in a clockwise direction. A stack of letters 36 rests edgewise on the floor 32 and it will be apparent that due to the described rotation of the rollers of the fioor and of the wall, the letters are dressed" to ensure un form relative positioning contiguous edges of the letters which rest on the rollers of the floor and against the rollers of the wall.

The stack of letters is supported by a back-rest (not shown) which urges the stack of letters along the floor 32 into engagement with a drive-out means for engaging the foremost letter of the stack and feeding it downwardly therefrom, as will hereinafter be more fully described. Conveniently, the said back-rest may take the form of the back-rest hereinafter described with reference to Figures 5 and 6, but having the back plate tilted rearwardly at a slight angle to the vertical thereby to facilitate the separation of the letters by the drive-out means.

The drive-out means comprises a drive-oil? belt assembly indicated generally at 37 and positioned adjacent one end of the floor 32 so that the belt engages the foremost letter of the stack, and an assembly of reverse running rollers indicated generally at 38 and positioned below the said one end of the floor 32 and co-operating with the drive-01f belt to prevent more than one letter being fed at a time. The drive-off belt assembly 37 comprises a pair of substantially L-shaped plates 39 pivotally supported at 40 so that the longer legs of the plates extend upwardly from the pivot 41 and the shorter legs extend in a direction away from the stacking floor 32. The

free ends 'of the shorter legs are secured together in spaced relation by a rod 41 to which is secured an upwardly extending rod 42 slidably supported in a Efixed bracket 43 and having mounted thereon a spring 44 and adjusting nut 45 so that the longer legs of the plates are resiliently urged in a direction towards the foremost letter of the stack and can be adjustably positioned with respect thereto by means of the adjusting nuts 45. The upper ends of the longer legs of the plates 39 are secured together in spaced relation by a spindle 46 upon which is rotatably supported a roller 47 around which passes an endless belt 48. The belt 48 also-passes over a driving roller (not shown) secured to a driving shaft constituting the pivot 40 and connected to a suitable driving means (not shown). The belt is tensioned by a tensioning roller 49 supported at the end of a pair of arms 50 and spring loaded into engagement with the belt by a spring 51. The belt 48 consists of a band of rubber faced material having a roughened surface and the roller 47, the drive roller and the tensioning roller 49 are formed with convex peripheral surfaces so that the belt is transversely convex in the direction of the letters to be engaged thereby.

The belt 48 is driven so that the roller 47 rotates in a clockwise direction as viewed in Figure 4 and it will be apparent that the belt provides a continuously downwardly moving surface which is resiliently engaged under the action of spring 44- with the front surface of the foremost letter 36 thereby to feed the letter downwardly from the stack.

The reverse running roller assembly 38 comprises two pairs of reverse running rollers 52 and 53 respectively supported on drive shafts 54 and 55, which shafts are connected to suitable drive means (not shown) for ro tating the reverse rollers in a clockwise direction as viewed in Figure 4. The respective pairs of rollers 52 and 53 are spaced lengthwise of the corresponding drive shaft so as to be spaced apart a distance greater than the width of the drive-off belt 48, so that in the assembled position of the apparatus the rollers of the respective pairs of reverse rollers are positioned one at each side of the drive-off belt 48.

The assembly 38 also includes a pair of driven rollers 56 supported upon a drive shaft 57 adapted to be rotated in a direction opposite to that of shafts 54 and 55, the said driven rollers being engaged by a pair of free running rollers 58 supported between the lower ends of brackets 59 pivoted upon the drive shaft 40 of the driveofl belt and spring loaded by means of a spring 69 in a direction towards the driven rollers 56 so that a letter fed downwardly from the stack by the drive-0E belt is engaged between the driven rollers 56 and the free running rollers 58 and driven further downwardly for subsequent handling, such as =for example in the cancelling and stacking apparatus of Figure 3.

The reverse running rollers 52 and 53 are supported by means of pairs of

brackets

61 and 62 respectively pivoted upon a common pivot provided by the drive shaft 57, the pairs of rollers 52 and 53 being thus independently adjustable towards and away from the drive-off belt 48. In order to provide for said adjustment, rods 63 and 64 are secured respectively at one end to the

brackets

61 and 62 and at their other end are connected to a positioning and spring loading arrangement 65 by means of which the pairs of

brackets

61 and 62 respectively can be angularly adjusted to move the reverse running rollers towards or away from the take-01f belt and also the pressure exerted by the reverse running rollers on a letter passing between the drive-ofi belt and the rollers can be adjusted.

In order to ensure adequate contact of a letter with the drive'oif belt there is provided a plurality of finger plates 66 between the brackets 61 and a further plurality of finger plates 67 between the bracket 62. The said finger plates have the same function as the shoe 15 of Figure 1 and are adjustable towards and away from the drive-off belt by means ofeccentric shafts which can be r tated by means of knobs 68 and 69 in ordm' to adjust the fingers 66 and 67 respectively to the desired position.

Thus, in operation of the apparatus described with reference to Figure 4, the foremost letter of the'stack is engaged by the drive-of1 belt 48 and driven downwardly thereby between the belt and the reverse running rollers 53 and 52, the effect of the reverse running rollers being to, cause transverse bowing'of the letter as described withreference to Figure 2, the fingers 66 and 67 ensuring that the bowed port-ion of the letter is maintained in engagement with the drive-0E belt.

As previously described with reference to Figures 1 and 2, the pressure exerted by thedrive-oif belt and the a reverse pressure exerted by the reverse running rollers bite of the driven and

free running rollers

56 and 58.

In Figures .and 6 there is shown one form of'stacking box suitable for use in the apparatus diagrammatically shown in Figure 3. The stacking box comprises a floor formed of a plurality of edgewise disposed strips 76. secured together in spaced parallel relation by bolts 71 and spacers 72, the bolts 71 being .anchored at one end in a side wall 73. The star-wheel 25 of Figure 3 is shown in Figure 5 as a plurality of star-wheels 74 supported upon a common shaft 75 extending through the wall 73 and connected to suitable drive means (not shown).

At the other end of the bolts 71 there is'secured a rail in the form of a strip 76 of greater width than the strips 79 and also a pair of brackets 77 which support therebetween a rod 78 of circular cross-section which thus extends along one side of the stacking floor in spaced relation therewith.

A back-rest is provided in the form of a substantially rectangular back plate 79 extending across the stacking fioor and upwardly therefrom, the said backing plate being secured at one end to a block 80 having a bore 81 extending thereth-rough and through which the rod 78 extends. The bore 81 is considerably largerthan the external diameter of the rod 78 and the block 80 is supported on the rod 78 by means of antifriction hearings in the form of two sets of four ball races 82 disposed at right angles one to another and engaging the peripheral surface of the rod 78, the block 80 and the back plate 79 secured thereto being thus supported on the rod 78 for sliding movement longitudinally thereof and for rotation with respect thereto. The back plate 79 will consequently drop by gravity towards the floor strips 70 and in order to support the back plate so that its lower edge clears the upper surface of the strips 70 a pair of ball races 83 mounted in a horizontal extension 84 of the block 89 engage the upper surface of the rail 76 there,

by to support the back plate clear of the fioonof the stacking box. By reason of the rota-table mounting of the block 80 on the rod 78, the backplate 79 can be swung laterally outwardly from the fioor of the stacking box when it is desired to remove a stack of lettersfrom the box. 7

The back plate is .urged in a directionftowards the star-wheels 74 by means of a spring 85 secured at one endto the rearmost bracket 77 and having attached to its'other end .a cord 86 which passes over apulley 87 and is attached to the block 80.

a We claim:

'1. Apparatus for stacking articles such as' letters and similar thin flat items of postal mail successively fed thereto in a stream in which the articles are spacedone from another in the direction of feed, the said apparatus comprising a first pair of driven rollers :for engaging each article as it is fed to the apparatus to feed the article in tothe apparatus, drive means for continuously rota-ting said first pair of rollers, a second pair of driven rollers positioned below said first pair of rollers ,for receiving articles therefrom and having their axes positioned on a line inclined with respect to a line passing through the axes of the first pair of rollers, thereby to change the direction of travel of'the articles as they pass through saidsecond pair of rollers, drive means for intermittently rotating said second pair of rollers, a stacking box positioned below said second pair of rollers for receiving articles therefrom and forming a stack of the articles, and article-operated means controlling the intermittent rotation of said second roller pair to vfeed the articles therethrough in .two time spaced steps co-ordinating with the passage of the anticles from the first pair of rollers, to cause'the leading edge portion of an article fed by the first roller pair to overlie the trailing portion of an article advanced one step through the second pair of rollers, whereby the articles are delivcred in .tiled relation .to the stacking box.

2. Apparatus as claimed in claim 1, in which said intermittent drive means comprises an electro magnetically operated single revolution clutch drivingly connected to said second pair of rollers, and said articleoperated means comprises a photo electric cell posi tioned at one side of the path of the articles as they are fed .to the apparatus, a light source positioned at the other side of said path for producing a beam of light traversing the path and impinging on the photo electric cell, and circuit means connecting the photo electric cell to the clutch, whereby upon interception of'the light beam by an article, the clutch is energised after a predetermined time interval to drive the second pair of rollers through one revolution;

3. Apparatus as claimed in claim 1, including printing means on the periphery of one of said second pair of rollers, whereby a stamp cancellationis applied to the articles as they are fed through said second pair of rollers.

References Cited in the file of this patent UNITED STATES PATENTS 1,035,716 Lynch et al Aug. 13, 1912 1,038,587 Ielfield Sept. 17, 1912 1,483,526 Smith Feb. 12, 1924 1,866,847 Finrock July 12, 1932 1,955,066 Hiller Apr. 17, 1934 2,734,743 Spurlino et a1. Feb. 14, 1956 2,813,717 Mentzer Nov. 19, 1957 2,844,373 Van Marle July 22, 1958 2,860,875 Staeger et al. Nov. 18, 1958