BACKGROUND OF THE INVENTION Field of the Invention

The present invention pertains to apparatus for feeding discrete pieces of sheet material and, in particular, mechanism for separating individual pieces to be dispensed from a magazine one at a time.

Description of the Prior Art

In many types of paper handling apparatus, such as envelope feeders and sheet feeders which are operated in conjunction with printing and word processing equipment, mechanism is provided for separating discrete pieces of sheet material so that the pieces may be dispensed from a magazine or stack one at a time and fed to the associated printing apparatus. The separation of discrete pieces of sheet material to assure that the pieces are fed seriatim to the printing apparatus has been a longstanding problem in the art of paper handling equipment. For example, in many types of sheet feeding apparatus it is desired that the apparatus be adapted to feed discrete pieces of different thickness such as single sheets of stationery as well as envelopes or folded pieces. One well known concept for sheet material feeding mechanisms provides for a slot of predetermined thickness formed in the bottom wall of a hopper or magazine, which slot is adjacent to a conveyor mechanism such as an endless belt or a set of feed rollers. Because of the small thickness

of most sheet material the thickness of the slot must be carefully controlled so that only one piece of material is dispensed through the slot when engaged by the dispensing conveyor mechanism.

Apparatus is also known wherein adjustable stops are provided to in effect control the thickness or height of the dispensing slot. However, when different thicknesses of sheet material are to be fed, the position of the stops must be changed which is a time consuming operation and is difficult to control to provide satisfactory per¬ formance. Although the aforedescribed type of mechanism is rel- atively reliable it requires precise settings and is limited to one particular material thickness or weight at a particular setting of the slot thickness.

Another known concept for so-called bottom dispensing feed mechanisms includes a magazine with a slot formed in a bottom side wall thereof below which is disposed a conveyor mechanism. Separation of discrete pieces of material which are engaged by the conveyor is accomplished by a spring biased retard member disposed adjacent to the slot outside of the magazine in the direction of. feed of the material. In this type of arrangement the retard member is biased against a conveyor belt which requires an unreasonable amount of power to drive the mechanism and causes rapid wear on the conveyor belt as well as the retard member. Furthermore, this arrangement usually requires a one way clutch to allow the conveyor belt to be run in the opposite direction for clearing a jammed condition of the separator mechanism. The resiliently biased retard member is also difficult to control with respect to the biasing force so that suitable feeding or dispensing can be obtained without jamming or crinkling the sheet material.

Prior art mechanisms are also known which utilize vacuum or compressed air jets for separating discrete pieces of sheet material. Such apparatus, of course, requires additional equipment in the form of pumps or compressors which add to the cost of the material feeding equiment or require a central source of compressed air or vacuum. A wide variety of automatic printing equipment is currently in development and in use for applications in business offices where sources of compressed air and/or vacuum are not available. Ae-

cordingly, sheet material feeding mechanisms which require pressure fluid or vacuum are not readily adaptable for many installations.

It has been determined in pursuing the present invention that it is desired to provide a separating mechanism for sheet material feeding equipment which is uncomplicated, reliable, adapted to separate discrete pieces of different thicknesses and surface finish and which may provide for easy clearing of a jammed condition of the feed mechanism if such should occur. Prior to the development of the present invention at least one or more of the problems and disadvantages discussed herein were associated with prior art sep¬ arator mechanisms.

SUMMARY OF THE INVENTION The present invention provides for an improved separator mechanism for use in sheet material feeding apparatus such as envelope and stationery feeders, which separator mechanism is adapted to reliably provide for separation of the piece of material to be fed from adjacent pieces of material retained in stacked relationship in a magazine or the like.

The present invention also provides for a separator mechanism for sheet material which provides for separation of discrete pieces of different thicknesses or weights without requiring any adjustments of the separator mechanism itself.

The present invention further provides a separator mechanism for use with sheet material feeding apparatus of the so called bottom feed type whereby stacked material may be dispensed in the same order that it has been stacked.

In accordance with the present invention there is provided apparatus for feeding discrete pieces of sheet material having a magazine with a longitudinal opening formed at the bottom of a side wall thereof. A conveyor mechanism is disposed adjacent to the opening and is engageable with the discrete pieces of material seriatim for dispensing said pieces through the opening. In ac¬ cordance with the present invention one or more resilient depending members are disposed across the opening and are adapted to be deflected by the edges of the pieces of sheet material whereby only

the piece engaged with the conveyor is allowed to pass out of the opening onto the feed path of the feeder apparatus. The resilient members are preferably formed of a flexible material such as natural or synthetic rubber. The resilient member is arranged as a cantilever beam in such a way that the greatest deflection is imposed on the beam by the piece of material which is desired to be dispensed from the material holding magazine. The resilent members also fric- tionally engage the piece of sheet material being dispensed to hold the same in firm engagement with the conveyor mechanism so that no slippage between the material and the surface of the conveyor mechanism is experienced which might result in damage to the material as it is being dispensed.

In accordance with the present invention an arrangement of a bottom feed type dispensing mechanism for discrete pieces of sheet material is advantageously used in combination with a conveyor mechanism comprises a plurality of cylindrical rollers having in¬ terposed therebetween fixed support members. Accordingly, the sheet material dispensing mechanism is relatively simple in con¬ struction and reliable in operation. Moreover, in the event that jamming of the feed path of the material should occur the path may be easily cleared due to the relatively simple structural arrangement which provides for dispensing and separation of the pieces of sheet material.

The present invention is particularly adapted to be used in conjunction with an envelope feeding apparatus of the type disclosed in co-pending U.S. Patent Application Serial No. 162,590 filed June 24, 1980 and assigned to the assignee of the present invention. Those skilled in the art will recognize that the present invention may, however, be readily adapted to other types of sheet material feeding apparatus including those types which dispense discrete pieces off of the top of a stack of sheet materiaL

The abovedescribed as well as other superior features of the present invention will be- further appreciated upon reading the detailed description which follows together with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a transverse section view of an envelope feeding apparatus of the type disclosed in the aboveidentified U.S. Patent Application and incorporating the improved separator mechanism of the present invention;

Figure 2 is a fragmentary perspective view of the envelope feeding apparatus illustrated in Figure 1 and showing the improved separator mechanism;

Figure 3 is a detail section view taken in the same plane as the section veiw of Figure 1 and showing the relative positions of the separator member and pieces of sheet material at the onset of feeding a piece of material from a stack; and

Figure 4 is a view similar to Figure 3 illustrating the manner in which only one piece of material is permitted to be dispensed from the stack.

DESCRIPTION OF THE PREFERRED EMBODIMENT , Referring to -the drawings and in particular Figure 1 an envelope feeding apparatus of the type disclosed in U.S. Patent Application Serial No. 162,590 is shown in transverse cross section and generally designated by the numeral 10. The apparatus 10 is particularly adapted to mount on a printer, not shown, having a rotatable cylindrical platen 12 for receiving an envelope or other piece of sheet material. The feeding apparatus 10 includes a frame generally designated by the numeral 14 comprised of suitable plate members including a member forming a front wall 16 and a member 18 forming a bottom wall of an envelope hopper or magazine generally designated by the numeral 20. The magazine 20 includes a removable plate 22 which is vertically moveable within the magazine and is operable to separate a stack of envelopes to be dispensed from the feeding apparatus to the aforementioned printer from envelopes received back to the magazine from the printer.

The apparatus 10 further includes a pair of spaced apart feed belts 24, one shown in Figure 1, which are trained over spaced apart pulleys 26 and 28 which are suitably rotatably mounted on the frame 14. The belts 24 are adapted to be driven by drive mechanism, not

shown, driveably engaged with the pulleys 28. The belts 24 are driven in timed relation with the rotation of the platen 12 for feeding envelopes into and out of the aforementioned printer. As shown in Figure 1 the feeding apparatus 10 is adapted to have a feed path, indicated by the arrows 30, which begins at an opening 32 formed between the bottom edge of the wall 16 and a plurality of spaced apart cylindrical rollers 34, also shown in Figure 2. Discrete pieces of sheet material such as envelopes 36 may be dispensed from the magazine 20 through the opening 32 and along the feed path 30 to a holding plate 38 which is provided with a yieldably biased holding member 40. Envelopes .are serially dispensed from the magazine 20 to the holding plate 38 whereupon they are engaged by spaced apart lugs 25 formed on the belt 24 and further fed along the feed path 30 into the platen 12. Further details of the structure and operation of the feeding apparatus 10 will not be discussed herein as they form no part of the present invention.

Referring also to Figure 2 the rollers 34 are mounted on a shaft 42 which may be driven by suitable mechanism, not shown, in conjunction with the mechanism which drives the belt 24 as described in U.S. Patent Application Serial No. 162,590. Disposed between the rollers 34 are extensions of the bottom plate 18 comprising spaced apart fingers 44. As shown in Figure 1 also, the fingers 44 are curved somewhat to conform to the peripheral surface of the rollers 34 and are positioned slightly below the surface of the rollers 44 adjacent to the opening 32. Accordingly, the fingers 44 are adapted to function as support members intermediate the rollers 34 for providing some support for a piece of sheet material being dispensed from the magazine 20. Although the fingers 44 are disposed slightly below the peripheral surface of the rollers 34 in the vicinity of the opening 32 the weight of a stack of envelopes 36 will cause the envelope adjacent to the rollers 34 to deflect slightly in the span between the rollers and engage the fingers 44.

The improved means for separating discrete pieces of sheet material being dispensed from the magazine 20, in accordance with the present invention, includes a resilient member, generally desig¬ nated by the numeral 46, which is characterized by a pair of

depending beam portions 48, as shown in Figure 2. The member 46 is suitably secured to the wall 16 by threaded fasteners 50 whereby the beam portions 48 are fixed to the wall 16 in cantilever fashion. The beams 48 depend across the opening 32 and extend between the spaced apart pairs of fingers 44 as shown in Figure 2. The member 46 is preferably formed of resilient material such as natural or synthetic rubber. In one embodiment of the present invention, used in conjunction with the apparatus 10 for feeding standard business letter size envelopes, the member 46 is formed of an elastomer having a hardness in the range of 40 to 50 durometer and having a thickness in the range of 2.25 to 3.20mm. In the aforementioned embodiment the width of the beam members 48 is preferably about 12.5mm. As illustrated in the drawing figures the beam members 48 extend downwardly between the respective pairs of fingers 44, as shown, and have their distal ends adjacent to the bottom surface of the fingers 44. Although the length of the beam members by itself is not critical, a proper relationship between length and thickness is . desirable to provide the proper wiping or separating function described hereinbelow. In operation, the dispensing rollers 34 are adapted to engage a piece of sheet material such as an envelope 36 which is at the bottom of the stack of envelopes, as shown in Figure 1. When the rollers 34 are rotated the frictional engagement between the rollers and the bottom envelope is sufficient to move the envelope towards and through the opening 32 as shown in Figure 3. However, the frictional forces between the bottom envelope and the envelope adjacent to it are such that as the envelope to be dispensed is moved through the opening 32 the next envelope as well as any additional envelopes which are not engaged with the wall 16 will tend to move through the opening with the envelope directly engaged with the rollers 34 until the edges of the envelopes engage the members 48 as shown. As the envelopes which are permitted to move through the opening 32 engage the members 48, the members are deflected in the direction of the feed path 30, the deflection being the greatest at the distal end 52 of the members 48.

Accordingly, as the bottom envelope 36 is dispensed from the magazine 20 the beam members 48 are deflected to engage and wipe across the surface of the envelope allowing the bottom envelope to be dispensed but retaining the remaining envelopes substantially within the magazine 20. The frictional retarding force applied to an envelope 36 ^' by the members 48 is less than the frictional force between the bottom side of the envelope and the rollers 34. However, the envelope adjacent to the bottom envelope engages the members 48 at a position closer to their point of attachment to the wall 16 and accordingly the resistence to deflection of the members 48 is greater at the point of engagement with the next-to-be- dispensed envelope and so on for any envelope that has moved through the opening 32 to engage the members 48. Accordingly, the provision of the cantilever beam members 48 disposed across the opening 32 provides a progressively greater resistence to deflection at the points where the beam members are engaged by those pieces of material which are desired to be retained in the magazine.

When the bottom envelope 36 is dispensed from the magazine 20 the next envelope, of course, becomes the bottom envelope and ^' if the rotation of the rollers 34 is continuous another piece of material is serially dispensed from the magazine 20. The provision of the resiliently deflectable members 48 does not require any precise control of the width of the opening 32 which is delimited by the bottom edge of the wall 16 and the peripheral surface of the rollers 34. In fact, the width of the opening 32 may be substantial to permit easier clearing of a jammed condition of the pieces of sheet material in the magazine 20 even though it is unlikely that such an event would occur with the arrangement according to the present invention. Furthermore, it will be appreciated from the foregoing description that the separating mechanism of the present invention does not require any precise assembly or alignment of parts of the feeding apparatus or adjustment thereof during its use.

It will further be appreciated that the arrangement according to the present invention permits the use of discrete pieces of sheet material of various thicknesses such as sheets of stationery, or relatively thick pieces of material such as folded brochures or

pamphlets. Although the present invention works particularly well with so called bottom feed magazines and associated conveyor mechanisms it is contemplated that the resiliently deflectable cantilever beam members 48 may be adapted to work with feeding apparatus where discrete pieces of material are separated at the top of a stack.

Those skilled in the art will recognize that detailed modifi¬ cations may be made in the present invention without departing from the scope or spirit of the invention which is recited in the appended claims.

OMP