Patent Application
20050242488
1. Field of the Invention
The present invention relates to a feeder device for a receiving apparatus and, more particularly, to a feeder device for feeding a medium to a device, the feeder device having an adjustably flexible feed gate apparatus, and associated method.
2. Description of Related Art
A printer device such as, for example, a printer as described herein, typically includes a feeder for supplying media, such as individual cards, to the printer, a print engine which includes a transport mechanism for transporting the card through the printer and a printing mechanism for printing on the individual cards, and an exit or output hopper for receiving the printed cards. Further, the feeder generally comprises a card hopper for receiving the stack of cards to be fed, in addition to a drive mechanism for feeding the cards to the print engine. A gate at the exit of the feeder, otherwise known as the outlet opening, can include a separation mechanism for separating individual cards, usually an end card, from the stack in order to feed only one card to the print engine at each feed cycle.
Such a card feeder may be used on other card processing systems, such as a patch lamination system, a magnetic card or smart card encoding system, or the like. The drive system generates the driving force for the end card and the separation mechanism generates a separation force on the stack so as to allow the end card to be separated therefrom. With such a card feeder system, a general intent is to provide a driving force on the end card that is greater than the separation force imparted on the stack under many conditions that can exist in the card feeder. The separation force exerted by the separation mechanism on the stack typically has to be greater than a sticking force that can exist between the end card and the remainder of the cards in the stack. This sticking force may be related to, for example, electrostatic discharge (“ESD”) between cards, cut or folded card edges, the weight of the stack on the end card, the thickness of the cards in the stack, or other factors or combinations thereof.
In order to address these concerns in a card feeder, a compromise often must be achieved between the separator mechanism, which exerts the separating force on the stack that must be greater than the sticking force between the stack and the end card, and the drive system, which must provide a driving force greater than the separating force, regardless of the type, thickness, condition, and quantity of the cards in the stack. As such, early card feeder devices implemented a fixed gate having a fixed dimension outlet opening generally corresponding to the thickness of a single card. However, such a configuration is generally effective only for the particular card thickness, and that effectiveness may be limited in instances of, for example, card thickness variation within the stack, or warped cards.
One further development was to provide a gate allowing for height adjustment of the outlet opening in correspondence with the thickness of the card to be fed. In such instances, the gate was provided with a movable blade, such as a cam-operated movable blade. However, the effectiveness of the movable blade configuration was also limited in instances of, for example, card thickness variation within the stack, or warped cards.
Other instances of such a card feeder include a flexible blade affixed to the gate so as to allow the outlet opening to vary in dimension to better accommodate the thickness of the card being fed. The flexible blade more readily accommodates card thickness variations within the stack or warped cards. However, the flexible blade may often be optimized for a particular card thickness or a narrow range of card thicknesses, and thus may not be applicable or effective for different card thicknesses or card thicknesses outside the optimal thickness range.
A further example of a card feeder is disclosed in U.S. Pat. No. 6,536,758 to Meier et al. The Meier '758 patent describes a feeder having movable gate with a flexible blade, wherein the gate/blade assembly is adjustable to accommodate various card thicknesses. That is, the cards are fed through an outlet opening in a hopper wall and the flexible blade reduces a height of the outlet opening to less than the thickness of the end card. As a card is passed through the outlet opening, the card contacts the flexible blade and the blade flexes in response. The control gate is movable to adjust the height of the outlet opening, the height corresponding to a particular contact between the card and the blade, where the contact is related to the separating force. Thus, for a particular gate position, the card being fed through the outlet opening may experience a different separating force depending on card thickness.
That is, if the card thickness increases over the card thickness corresponding to the position of the gate, a larger portion of the blade contacts the card fed through the outlet opening. The increased contact with the blade thereby increases the separating force and, depending on the thickness of the card, the separating force can become greater than the driving force provided by the card drive. Such an occurrence may undesirably cause card misfeeds. On the other hand, if the card thickness decreases compared to the card thickness corresponding to the position of the gate, a smaller portion of the blade contacts the card fed through the outlet opening. The thinner card thereby experiences a decreased separating force due to the decreased contact with the blade and, as a result, the separating force can become lesser than the sticking force between cards. Such an occurrence may undesirably cause double-feeding of the cards.
While the Meier '758 patent allows the gate to be moved so as to accommodate varying card thicknesses by varying the separating force, the range of card thicknesses that can be fed at each gate position may be limited or a large number of closely spaced gate positions may be necessary for the card feeder to be effective over a large range of card thicknesses. This limitation may be at least partially due to the particular configuration of the flexible blade, which may have a flexibility only be suitable for narrow range of card thicknesses. That is, the gate adjustment is related to the contact between the blade and the card fed through the outlet opening, which is generally effective for a range of card thicknesses, while the blade flexibility is selected to provide a particular range of separating force. As such, if a particular card has a thickness toward a high end of the thickness range, the blade may not provide a suitable separating force for the card greater than the sticking force between cards, while a card thickness toward a low end of the thickness range may experience a separating force from the blade that exceeds the driving force from the card drive.
Thus, there exists a need for a feeder device capable of supplying media, such as cards, stock, paper, cardboard, etc. to a print engine in a secure, reliable, and efficient manner, without such undesirable occurrences as, for example, multi-card feeding or misfeeds, if the hopper is not empty. Such a feeder device should desirably provide effective media feeding for different types of material, for different thicknesses, and for media throughout the stack of media, from the first media unit to last media unit in the stack.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
As an initial point, the present invention relates to apparatuses and methods for feeding individual media units to a receiving apparatus. The disclosure provided below demonstrates use of the apparatuses and methods in a card printer, where the individual media units are cards. It will be understood that the examples of the use of embodiments of the invention provided below should not be seen as limiting the invention to printers and card media. The specific examples herein are merely presented here so as to provide a more complete understanding of the invention and not to limit the scope of the invention. For example, the apparatuses and methods of the present invention can be used in any environment where individual media from a stack of media is provided to a receiving apparatus. Such apparatuses and methods can be used to provide media, such as cards, stock, paper, cardboard, etc. to a printer, to provide labels or other stock material to a production line, etc.
As further detailed herein, one embodiment provides a feeder device adapted to feed a medium, such as a card, stock, paper, cardboard, etc. to a receiving apparatus, such a printer, copier, etc. The feeder device is adapted to feed the end media unit from a plurality of media units to a receiving apparatus, wherein each media unit has a thickness and the plurality of media units forms a stack. Such a feeder device comprises a drive mechanism adapted to drive the end media unit of the stack in a feed direction through a gate apparatus. The gate apparatus defines an opening and is aligned with the drive mechanism such that the drive mechanism is capable of feeding the end media unit in the feed direction through the opening. The opening extends from a first edge to a second edge of the gate apparatus so as to define a fixed height, greater than the thickness of the end media unit. A flexible blade member is fixedly engaged with the gate apparatus at a fixed end and is cantilevered with respect to the gate apparatus so as to define a free end. The blade member defines a length between the fixed end and the free end, and extends from the first edge toward the second edge so as to effectively reduce the height of the opening. The blade member is further configured such that the flexibility thereof is adjustable, wherein the adjustable flexibility of the blade member is thereby adapted to allow the feeder device to feed media units of varying thickness to the receiving apparatus.
Another advantageous aspect detailed herein comprises a method of feeding a medium, such as a card, stock, paper, cardboard, etc. to a receiving apparatus, such a printer, copier, etc. The feeder device comprises a drive mechanism, a gate apparatus, and a flexible blade member. Each media unit has a thickness and the plurality of media units forms a stack. First, the end media unit of the stack is fed in a feed direction with the drive mechanism, through an opening defined by the gate apparatus and aligned with the drive mechanism. The opening extends from a first edge to a second edge of the gate apparatus so as to define a fixed height greater than the thickness of the end media unit. The blade member is fixedly engaged with the gate apparatus at a fixed end and is cantilevered with respect to the gate apparatus so as to define a free end. The blade member defines a length between the fixed end and the free end, and extends from the first edge toward the second edge so as to effectively reduce the height of the opening. The flexibility of the blade member is then adjusted so as to allow the feeder device to feed media units of varying thickness to the receiving apparatus.
The drive mechanism 200 is configured to provide a driving force for acting on the end card 450 from the stack 400. The driving force may be provided by, for example, a conveyor-type belt, drive roller(s), or the like, rotating or otherwise advancing in the feed direction 210 such that contact thereof with the end card 450 causes the driving force to be applied to the end card 450. The driving force urges the end card 450 toward the opening 310. In one embodiment, the driving mechanism 200 comprises a conveyor-type belt, as shown in
Generally, in order to separate the end card 450 from the stack 400, such that only the end card 450 is fed through the opening 310 to the print engine 500, a separating force is required in opposing relation to the driving force. That is, a separating force must typically be applied at least against the card in the stack 400 that is adjacent to the end card 450, so as to prevent the sticking force from causing the adjacent card to be affected by the driving force and also driven in the feed direction 210. Accordingly, as previously discussed, the separating force is desirably greater than the sticking force so as to prevent feeding of multiple cards toward the print engine 500. However, due to, for example, variations in card thickness or other factors, the separating force, in some instances, is at least partially applied to the end card 450, as well as the adjacent card in the stack 400. As a result, the separating force preferably does not exceed the driving force since, if the driving force is greater than the separating force, a misfeed or non-feed of the end card 450 may occur.
As shown in
A flexible blade member 600 is operably engaged with the gate apparatus 300 so as to extend across the first edge 320, from the first edge 320 toward the second edge 325 so as to reduce the height of the opening 310. In one embodiment, for example, the blade member extends to within about 0.1 mm of the second edge 325 of the opening 310. The blade member 600 is comprised of a flexible material such as, for example, a thermoelastic material. In one embodiment, the blade member 600 is comprised of a silicone elastomer, such as a silicone rubber, having a hardness of, for example, between about 50 and about 70 Shore (Durometer). However, one skilled in the art will appreciate that the hardness of the material is but one factor determining the suitably of the blade member 600 for the purposes described herein. That is, many other factors regarding the blade member 600 and associated components may otherwise determine the suitability of the blade member 600 for the purposes described herein and any exemplary configurations described herein are not, in any way, intended to be limiting with respect to alternate configurations.
In one embodiment, as particularly shown in
As previously discussed, the drive mechanism 200 drives the end card 450 toward the opening 310, but other cards in the stack 400 may tend to follow the end card 450 toward the opening due to the sticking force between cards. One purpose of the blade member 600, in this regard, is to exert a net separating force on the other cards in the stack 400, greater than the sticking force between cards, so as to allow the end card 450 to be separated from the stack 400. Accordingly, the driving force on the end card 450 must be greater than the separating force exerted by the blade member 600 on the end card 450 to allow the card 450 to be fed to the print engine 500.
One skilled in the art will appreciate that the discussion herein of the behavior of the flexible blade member 600 is a simplified treatment of the underlying mechanical or other modeling principles applicable to the configuration of the blade member 600 and its interaction with other components. For example, a cantilever beam model may be appropriate and applicable to a cantilevered blade member 600 as discussed in relation to selected embodiments of the present invention. Accordingly, the simplified discussion presented herein is provided as an exemplary illustration of the principles and behavior underlying the various embodiments of the present invention and is not intended to be limiting in any manner with respect to the various models, which may be implemented to analyze various embodiments with increased detail. In addition, one skilled in the art will also appreciate that there may be many different manners of operably engaging the blade member 600 with the gate apparatus 300 and/or the adjusting member 700. Accordingly, the interaction between the blade member 600, the gate apparatus 300, and/or the adjusting member 700 may, in such instances, be represented by a model other than a cantilever beam model. Accordingly, the configurations presented herein are for example only and are not intended to be limiting with respect to the interaction between the blade member 600, the gate apparatus 300, and/or the adjusting member 700.
Having presented a basic overview of the behavior of a cantilevered blade member 600, additional aspects of the present invention are now addressed. More particularly, some embodiments of the present invention further include an adjusting member 700 (otherwise referred to herein as an “adjustment element”) operably engaged with the blade member 600 so as to allow the flexibility of the blade member 600 to be adjusted to accommodate different ranges of card thicknesses.
The feeder device 100 may be configured to feed cards having varying thickness. As a result of varying card thickness, sticking force between cards, and/or other factors, the separating force exerted by the blade member 600 may vary. The blade member 600 may thus have a range of card thicknesses (also referred to herein as “the optimal thickness range”) over which the relationship of driving force (Fd)>separating force (Fsp)>sticking force (Fst) remains valid. If the thickness of the card falls below the optimal thickness range, the end card 450 contacts the blade member 600 closer to the free end 620. However, since the blade member 600 has a substantially constant thickness 630 along its length 625, the flexibility or elastic modulus of the blade member 600 is also substantially constant along the length 625. That is, the thinner end card 450 contacts the blade member 600 further away from the fixed end 610, where the resistance of the blade member 600 to deflection decreases, as compared to a card within the optimal thickness range. Accordingly, the separating force exerted by the blade member 600 toward the free end 620 may decrease to less than the sticking force, thereby undesirably increasing the risk of multiple card feeding. Conversely, for a card thickness above the optimal thickness range, the card 450 contacts the blade member 600 closer to the fixed end 610, where the resistance to deflection increases, as compared to a card within the optimal thickness range. As such, the separating force exerted by the blade member 600 toward the fixed end 610 may increase to more than the driving force, thereby undesirably increasing the risk of misfeed or no card being fed.
As shown in
In such a configuration, one skilled in the art will appreciate that the adjusting member 700 essentially changes the fixed point or mounting of the cantilevered blade member 600, wherein a shorter cantilever increases the resistance of the blade member 600 to flexing (a greater separating force), while a longer cantilever decreases the resistance of the blade member 600 to flexing (lesser separating force). In some instances, the magnitude of the separating force may be correlated with card thickness. That is, a particular card thickness range may require a particular separating force, wherein a card thickness at or above the upper end of the range may required a decreased separating force and a card thickness at or below the lower end of the range may require an increased separating force. As such, the adjusting member 700 may be disposed at a particular setting with respect to the blade member 600 so as to provide a separating force, via the blade member 600, suitable for a certain card thickness range. For example, where card thicknesses range from about 9 mils to about 60 mils, the flexibility (or capability of providing a necessary separation force) of the blade member 600 may be adjusted by the adjusting member 700, for instance, to one of three discrete settings to provide three card thickness range subsets. A setting of the operable portion 710 of the adjusting member 700 closest to the first edge 320 of the opening 310 may provide the smallest cantilever of the blade member 600 and a suitable separating force, for example, for cards having a thickness of between about 9 mils and about 13-14 mils (“small thickness cards”). A setting of the operable portion 710 of the adjusting member 700 closest to the fixed end 610 of the blade member 600 may provide the largest cantilever of the blade member 600 and a suitable separating force, for example, for cards having a thickness of between about 18 mils and about 60 mils (“large thickness cards”). A setting of the operable portion 710 of the adjusting member 700 medially between the fixed end 610 and the first edge 320 may provide a medium cantilever of the blade member 600 and, as such, a suitable separating force, for example, for cards having a thickness of between about 12 mils and about 20-25 mils (“medium thickness cards”).
One skilled in the art will appreciate, however, that many different adjustability schemes may be implemented in order to provide the necessary degree of adjustable flexibility of the blade member 600, within the scope of the present invention. For example, in contrast to the discrete flexibility range adjustments, as discussed, the adjusting member 700 may be configured to be substantially continuously adjustable between the fixed end 610 and the first edge 320. In other instances, the thickness 630 of the blade member 600 may vary along the length 625 thereof (the cross-sectional profile of the blade member 600 may be non-uniform) and, as a result, interaction of the adjusting member 700, if used or necessary, may provide different flexibility or stiffness characteristics of the blade member 600 as compared to a blade member 600 having a uniform cross-sectional profile. In further instances, the flexibility or stiffness characteristics of the blade member 600 may also be configured to vary laterally across the width of the opening 310. For example, the blade member 600 may be configured to provide a separating force in a medial position with respect to the opening 310. That is, in some instances, the blade member 600 may not extend completely across the width of the opening 310, leaving a gap between each side 330, 335 of the opening 310 and the blade member 600. In other instances, the blade member 600 may be, for example, divided into segments, in a similar manner to the fingers or tines of a comb, selectively disposed, or disposed at selected intervals, across the width of the opening 310. Further, the free end 620 of the blade member 600 may be nonlinear, but otherwise configured so as to provide the necessary distribution of separating force across the opening 310.
In still other instances, the flexibility or stiffness characteristics of the blade member 600 may be influenced and/or determined by, for example, the material comprising the blade member 600. That is, with respect to the adjustable flexibility or stiffness of the blade member 600, the degree of flexibility or stiffness of the blade member 600 may be less sensitive with respect to the position of the adjusting member 700 as the material comprising the blade member 600 increases, for example, in hardness, thickness, or modulus of elasticity. For instance, a blade member 600 comprised of silicone rubber having a hardness of about 70 Shore (relatively harder and less flexible) may be less sensitive to the actual position of the adjusting member 700 for providing a desired separation force, than a blade member 600 comprised of the same silicone rubber material and having the same thickness 630, but having a hardness of about 50 Shore (relatively softer, less stiff, and more flexible). In another example, varying the thickness 630 of the blade member 600, while maintaining the same hardness of the silicone rubber material, may also serve to vary the flexibility or stiffness of the blade member 600. That is, for the same hardness of material, a thicker blade member 600 may exhibit less flexibility or more stiffness than a thinner blade member 600 and, as such, a thicker blade member 600 may be less sensitive to the actual position of the adjusting member 700 for providing a desired separation force, when interacting therewith.
Any of the principles discussed herein regarding the adjustably flexibility or stiffness of the blade member 600 may also be applicable to different configurations of the blade member 600 itself. For instance, as shown in
In another example, as shown in
As mentioned in the above embodiments, the position of the adjusting member 700 should generally correspond to the thickness of the card being fed. The position of the adjusting member, for determining the flexibility or stiffness of the blade member 600, may be controlled manually, such as being manually positioned by the operator of the printer. Further, the adjustment of the adjusting member 700 may be automatically performed. By using an automatic positioning system for the adjusting member 700, the apparatuses and methods of the present invention may dynamically adjust to card thickness and thus be more effective, for example, in instances where the card thickness of the cards in the stack varies. For instance, the apparatuses and methods may adjust to the thickness of a card without operator input. As such, the operator could, in some instances, load a stack having cards of different thickness, with the apparatuses and methods automatically adjusting the position of the adjusting member 700 to accommodate the thickness of each card.
With respect to positioning the adjusting member 700,
Various views of a feeder device 100 according to one particular embodiment of the present invention are shown in
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, the adjustably flexible feed gate apparatus described herein may be advantageously combined with a feeder device 100 having aspects directed to improving conditions under which cards are fed to the print engine 500. Such aspects of the feeder device 100 are described in, for example, U.S. patent application Ser. No. ______, entitled “FEEDER DEVICE HAVING INCREASED MEDIA CAPACITY AND MULTIPLE MEDIA THICKNESS FEED CAPABILITY AND ASSOCIATED METHOD,” filed concurrently herewith. The referenced patent application discloses, for example, that the adjustably flexible feed gate apparatus described herein may be combined with a hopper configured to hold cards to be fed in such a manner as to reduce the sticking force acting on the end card 450, and to reduce the effect of the weight of the other cards in the stack 400 on the end card 450. Such a feeder device 100 may also include a mechanism between the hopper and the gate apparatus 300 configured to facilitate separation of the end card 450 from the stack 400, and to increase the driving force on the end card 450 by increasing contact with the drive mechanism. In other instances, the blade member 600 described herein may vary considerably in terms of, for example, the type and characteristics of the material comprising the blade member 600, the texture of the surfaces of the blade member 600, and/or the shape or configuration of the free end 620. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
