US3420149A - Sheet feeding apparatus - Google Patents

Description

Jan. 7, 1969 s. w. MIDDLEDITCH ETAL 3,420,149

51mm FEEDING APPARATUS Filed Sept. 13, 1965 jwimwwm VMWM' United States Patent 3,420,149 SHEET FEEDING APPARATUS Stanley William Middleditch, Little Heath, Potters Bar, and Victor Richard Sels, Sidcup, England, assignors to De La Rue Instruments Limited, London, England, a corporation of Great Britain Filed Sept. 13, 1965, Ser. No. 486,721 Claims priority, application Great Britain, Sept. 25, 1964,

39,204/ 64 US. Cl. 9393 2 Claims Int. Cl. B65h 33/00 ABSTRACT OF THE DISCLOSURE This invention deals with that type of apparatus for sequentially feeding sheets which comprises a support means, capable of supporting a stack of sheets, and means for biasing the foremost sheet of the stack against rotary feeding means capable of engaging and feeding sheets singly through a gauging throat.

In one such known arrangement the throat comprises a precise gap formed between a pair of stationary nonyieldable members positioned at the front of the stack and adjusted so as to permit one sheet to pass through at a time. This arrangement, whilst being satisfactory for sheets with newly cut edges, possesses an inherent tendency to jam when used in conjunction with used sheets having worn or imperfect edges.

A second known arrangement, the throat comprises a gap defined by the extremity of a stationary support member for the stack of sheets, or attachment thereto, and the periphery of a driven resilient frictional feeding roller or belt, which is capable of engaging and propelling the leading edge of the foremost sheet of the stack into a roller system. By this arrangement the frictional material serves the combined functions of gauging and transporting the cards, but, as the former function is highly exacting, it is inevitable that frequent adjustment is necessary to compensate for wear, or change of resilience, to ensure complete reliability.

It is the object of the invention to overcome the aforementioned disadvantages by the provision of an arrangement that combines the desirable features of a precision non-yieldable throat with those of the roller type, the arrangement being such that imperfect sheet edges are assisted through the restricted opening in a reliable manner and without damage to the sheets.

According to the present invention in apparatus of the type described for sequentially feeding sheets as hereinbefore defined the throat is defined by a precise gap formed between a stationary member forming a part of, or attached to, the support means and the periphery of a non-yieldable driven roller. The roller is preferably mounted on a transverse shaft which has its axis substantially in alignment with the working surface of the support means, and which also carries a frictional main feed roller assembly, spaced from the said throat and adapted to engage the leading edge of the foremost sheet in the stack.

Preferably an auxiliary frictional feed roller assembly is provided to engage the face of the foremost sheet at Patented Jan. 7, 1969 points remote from its leading edge. This assembly may comprise a pair of spaced feed rollers driven at the same peripheral speed as that of the non-yielda'ble roller.

Preferably the apparatus includes at least one pair of co-acting power driven conveying rollers, capable of engaging a sheet whilst it is still in frictional contact with the main feed roller assembly. The conveying rollers are adapted to be driven at a faster peripheral speed than that of the non-yieldable roller so that gaps are formed in the stream of sheets delivered from the gauging throat.

Preferably also the apparatus incorporates a delivery stage capable of receiving sheets delivered by the conveying rollers. The delivery stage may conveniently comprise a driven stacking roller and an associated yieldable sheet backing member, said member being inclined with respect to the flow line of the sheets, thereby to define a wedge opening for the receipt of the sheets.

Preferably means are provided to count sheets delivered from the gauging throat; such means may conveniently be of the optical type capable of advancing a digital counter at the passage of each sheet.

The invention will now be described with reference to the accompanying drawing in which FIGURE 1 is a diagrammatic vertical centreline section of a sheet feeding apparatus incorporating supply and delivery stages and an intermediate counting means, and FIGURE 2 is a fragmentary end view of some of the components shown in FIGURE 1. It should be noted that structural and driving components have been omitted for reasons of clarity, but these are not critical and may be varied to suit the desired circumstances.

Referring to the drawings, the apparatus comprises a sheet supply stage, generally denoted by symbol S, which stage comprises a horizontal platform 1 capable of supporting a stack of sheets 2A on edge, and a slidable pusher member 3, biased by means of a compression spring 4, to cause the foremost sheet to bear against a pair of spaced auxiliary feed rollers 5, 6, the peripheral surfaces of which are of resilient material e.g. rubber. These rollers 5, 6 are rigidly secured on a transverse shaft 7 which is driven by means of a gearing system (not shown). The axis of the shaft 7 is mounted parallel to, and at a higher level than, the top of the platform 1, so that the rollers will contact the foremost card at two spaced zones remote from its lower edge. The pusher member 3 includes an inclined front face 8 arranged to cause the stack of sheets 2A to bear against the auxiliary feed rollers 5 and 6 in the manner shown.

A second transverse driven shaft 9, mounted below the shaft 7 and in horizontal alignment with the upper surface of the platform 1, carries a central non-yieldable roller 10, e.g. of steel, and a pair of outwardly spaced rubber-surfaced main feed rollers 11, 12. In the vicinity of the roller 10, the front edge of the platform 1 is chamfered at 13 and the chamfered portion together 'with the roller 10, form a gauging throat T the dimension of which may be adjusted by means of a screw 14 and integral control wheel 15 in conjunction with a tapped nut 16 attached to the underside of the platform 1.

Two pairs of power driven conveying rollers, one of each pair of which is indicated at 17 and 18, are mounted on transverse shafts 19 and 20 respectively, below the gauging throat T so as to be capable of seizing the sheet before it has been released from the main feed rollers 11, 12. The conveying rollers 17, 18 are driven at a fast peripheral speed than the rollers 5, 6, 10, 11 and 12 so as to increase the velocity of the sheet and form a larger gap, and consequentially a longer time interval, between successive sheets. The conveying rollers 18 are provided with rubber peripheries to afford a satisfactory grip on the sheets.

A sheet counting stage comprises a source of illumination 21 and a photo-electric cell 22 positioned in close proximity 'below the conveying rollers 17 18. The cell 22 is connected to any known form of electronic amplifier A, the output of which is in turn coupled to a digital counter C, of any known construction.

The delivery stage, generally denoted by symbol D, comprises a support platform 23 onto which a pusher member 24 is capable of sliding against the action of a compression spring 25. The platform 23 is formed with an .upwardly inclined guide portion 23a, slotted to allow operation of the conveying rollers 17, photo-electric cell 22 and stacking wheels 26, plurality of which wheels 26 are mounted on a driven shaft 27 connected to the main drive of the apparatus by a suitable gearing system. The stacking wheels 26 are provided with rubber tyred peripheries which are capable of contacting the rear faces of the sheets and propelling them downwards in a positive manner against the working surface of the platform 23; the positioning of the stacking wheels 26 and the pusher member 24 is such as to provide a wedge-opening at the front of the support member 23. A sheet 2B is shown passing through the conveying rollers and entering the delivery stage.

In operation, the pusher member 3 is first manually retracted against action of the spring 4 and a stack of sheets 2A is positioned on the platform 1. When the pusher member 3 is released, the foremost sheet is pressed against the feeding rollers 5, 6, 10, 11 and 12. Upon zeroizing the counter unit and starting the drive of the apparatus, the sheets will be sequentially fed in a downward direction through the gauging throat T, after which they will be accelerated by the conveying rollers 17 and 18 and delivered to the wedge opening formed at the front of the support platform 23. Every time a sheet such as 2B passes in front of the light source 21, a fluctuation will be created in the photo-electric cell 22 and an electrical pulse will be amplified and recorded by the counter unit C. As sheets are successively delivered the spring-loaded member 24 will be horizontally displaced to permit the stack to be built up as shown at 2C. When the whole stack of sheets have been moved from the supply stage S to the delivery stage D, the counter unit C will register the total number contained in the stack at the said stage D. If it is desired to feed a predetermined quantity of sheets to the delivery stage D, it is only necessary for the operator manually to arrest the foremost sheet in the stack 2A in accordance with the digital counter C, and thus promote a deliberate slippage between it and the feeding rollers. Alternatively the counter C may incorporate means automatically to arrest the driving means when a predetermined total has been recorded. Additionally it may be arranged for the driving motor circuit to be broken when the supply stage S is exhausted by the provision of a suitable limit switch. Furthermore the re traction of the pusher member 3 may be carried out automatically or alternatively through the medium of a linkage system originating from a conveniently'arranged operating handle externally of the apparatus.

What is claimed is:

1. Apparatus for sequentially feeding sheets comprising sheet support means for supporting on edge a stack of sheets, rotary feed means adjacent said sheet support means for feeding said sheets one by one from said sheet support means, means for biasing the foremost sheet of the stack towards one end of said sheet support means and against said' rotary feed means, and non-yieldable roller means fixedly positioned adjacent said one end of said sheet support means and spaced from said one end for providing a precisely dimensioned gauging throat between said non-yielding roller means and said one end for passing singly sheets of predetermined thickness, said rotary feed means comprising a pair of frictional feed rollers mounted on each side of said non-yieldable roller means on a common shaft, the axis of said shaft being substantially in alignment with the working surface of said sheet support means, said frictional feed rollers being spaced from said gauging throat and being positioned to engage the leading edge of the foremost sheet in the stack, the apparatus further comprising conveying means for conveying the sheets from the area of said throat, said conveying means comprising further roller means for engaging each sheet fed singly through said throat while each sheet is still in contact with said rotary feed means, and for frictionally conveying each said sheet away from said throat at a speed greater than the peripheral speed of said rollers, whereby said sheets are spaced apart as they leave the throat, sheet counting means for detecting and recording the passage of each sheet, and sheet receiving means for receiving the conveyed sheets.

2. Apparatus according to claim 1 wherein said sheet receiving means comprises means for receiving the sheets conveyed thereto in substantially the same plane as the plane of the stacked sheets.

References Cited UNITED STATES PATENTS 852,100 4/1907 Bullard 271-62 2,787,363 4/1957 Howdle 93-93 X 3,087,725 4/1963 Duncan 27171 3,186,316 6/1965 Lenk 93-62 3,239,676 3/1966 Pali 93-93 X 3,280,679 10/1966 Huffman 93-93 X FOREIGN PATENTS 625,269 8/1961 Canada.

TRAVIS S. MCGEHEE, Primary Examiner.

US. Cl. X.R. 27171

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