CARD FEEDING APPARATUS
Technical Field
The present invention relates to apparatus that feeds an individual card from a card stack into a feed path. Background Art
The term "card" as used herein, generally refers to flat flexible cards that are formed of a material that has a memory or stiffness — memory or stiffness in this disclosure refers to the ability of a flexible card when curved or bowed to return to a flat condition. Such material can be, for example, polycarbonate, polyester, or resin coated paper. Examples of cards are playing cards, ID cards, business cards, credit cards, drivers' licenses and photographic paper.
Information is often printed on a card, such as an ID card. When printing on an ID card, such cards are arranged in.a card stack and placed in a hopper. They are serially fed by a feeding mechanism from the hopper into a feed path to a work station such as a printing press, where they are printed. Because of the stiffness of cards, misfeeding of cards is a problem. In a first approach, card feeding mechanisms feed individual cards by restraining the corners of a card as the card is fed. With this approach there is a danger of damage to the card. A second approach to feeding cards from the bottom of a stack of cards through an opening can be explained with reference to U.S. Patent Nos. 715,764 and 2,280,964. In this approach, the bottom card of a card stack is supported on leading and trailing wall lips of a hopper. Between these lips is an opening. A roller engages the unsupported portion of the bottom card and rotates in a first direction causing the leading portion of the bottom
card to move downwardly through the opening. The direction of rotation of the roller is reversed and the card is fed from the hopper. When individual cards are fed by this arrangement, isfeeds of cards can be a problem.
Disclosure of the Invention
Accordingly, it is an object of this invention to provide an improved card feeding apparatus which prevents misfeeds and feeds an individual card from a card stack into a feed path to a high speed printing apparatus without damaging corners or edges of the card. It has been determined experimentally that if the unsupported portion of the card can be displaced vertically from the supported portions, cards can be fed without misfeeds by the above—described second approach.
In accordance with a disclosed embodiment of this invention," there is provided apparatus for eeding a card from. a stack of cards" along a feed path, comprising: a hopper having leading and trailing wall members constructed to constrain a card stack therebetween and leading and trailing wall lips constructed to support the leading and trailing end portions of said bottom card of such card stack and define a bottom opening between said leading and trailing lips; said leading and trailing walls being configured to bow the cards of a card stack constrained therebetween so that the unsupported middle portion of the bottom card extends through the said bottom opening; and engaging means effective in a first condition for engaging the unsupported portion of a bottom card and moving the leading portion thereof out of its supported relation with said leading wall lip.
Brief Description of the Drawings
Fig. 1 is a sectional view of a feeding apparatus taken along the lines 1-1 of Fig. la;
Figs, la—lc show various stages of operation of the feeding apparatus of Fig. 1 in accordance with the invention; and
Figs. 2a—2c show various stages of operation of another embodiment of feeding apparatus in accordance with the invention. Description of the Preferred Embodiment
Turning now to Fig. 1 and Figs, la-lc, there is shown a feeding apparatus 10. The apparatus 10 successively feeds the bottom card from a card stack 16 seriatim into a feed path shown by arrow 12. As shown in Fig. 1 and Fig. la, a hopper 14 includes leading and trailing wall members 13 and 15, respectively, that are constructed to receive and constrain "a card stack 16 therebetween. At the bottom of the walls 13 and 15 there are provided leading and trailing wall lips 14a and 14b respectively for supporting the leading and trailing portions of the bottom card of the card stack 16. Between the wall lips 14a and 14b a bottom opening is defined through which the bottom card of the card stack is fed. As shown in Fig. la, a backer plate 18 is received in the hopper 14 and has a surface which is slightly curved, and is adapted to engage the top card of the card stack 16. A spring 20 applies a force to the backer plate 18, which in turn applies a force to the card stack 16. The applied force presses the bottom card of the stack against the wall lips 14a and 14b. The distance between walls 13 and 15 is less then the length of the cards of the stack. This constrains the card stack and bows the cards of the stack as shown. The arrangement is such that the unsupported portion of the bottom card extends downwardly through the opening and is offset
vertically relative to its supported portions on wall lips 14a and 14b. The amount of vertical offset can be determined experimentally. For example, a polycarbonate ID card having the dimensions 0.117 mm thick, 59.738 mm wide and 89.170 mm long was supported on its shorter width edges by the wall lips 14a and 14b respectively. The unsupported middle portion was offset vertically from the supported portions by about 6.350 mm. This vertical offset was found to prevent misfeeds.
A roller 22 is eccentrically mounted on a rotatable shaft 24. As shown in Fig. 1, a motor M drives a gear 26 which is in mesh with a gear 28 fixed to the shaft 24. The motor M is reversible and can selectively rotate in opposite directions. In its inoperative position shown in Fig. la, the surface of the roller 22 is spaced from the bottom card of the card stack 16. As shown in Fig. lb, by rotating the roller 22 in a clockwise direction, a position is reached where the roller surface engages the unsupported portion of the bottom card of the stack 16, and while the trailing portion 16b of the bottom card is held in the hopper, trailing portion 16b of the bottom card buckles. The leading portion 16a of the bottom card pulls away from the lip 14a and with a snapping action moves downward. The leading portion 16a of the card 16 due to its stiff¬ ness, straightens out and is now lower than the lip 14a (see Fig. lb). In other words, by rotating the roller 22 in a clockwise direction, the bottom card is driven towards the rear of the hopper, causing it , to buckle. This action causes the front portion 16a to free itself from the front of the hopper and snap downwardly through the bottom opening defined between the wall lips 14a and 14b.
As shown in Fig. lc, when the motor M reverses its direction, it drives the eccentrically
mounted roller 22 in a counter clockwise direction. This movement of the roller 22 causes the bottom card of the card stack to positively move into a feed path 12 out of the hopper 14 and into a feed mechanism shown by feed rollers 30.
Turning now to Figs. 2a-2c which show another embodiment of the invention. The same reference numerals as shown in Figs. 1 and la—e will be used where identical parts are shown. It should be noted that walls 13 and 15 are constructed to constrain the card stack 16 and to bow the cards of such stack as in the previous embodiment. As shown in Fig. 2a, the roller 22 is in a disengaged position from the bowed unsupported portion of the bottom card of 'the card stack 16. The roller 22 is rotatably mounted on a bifurcated member 40, which is pivotally mounted on a shaft 42. A spring 44 is connected to the member 40 and rotates it and the roller 22 to the disengaged position. When energized, a solenoid 46 translates a member 48 causing it to engage the bottom portion of the member 40. The member 40. rotates in a counter clockwise direction carrying with it the roller 22. When the roller 22 contacts the bowed unsupported portion of the bottom card of the stack 16, a drive motor (not shown) is energized and the roller 22 rotates in a clockwise direction until the bottom sheet is in the position shown in Fig. 2b. Although not shown, it will be understood that a ssnsor can be provided which detects the buckle 16b in the rear portion of the bottom card and de-energized the motor.
With the solenoid 46 remaining energized, the drive motor (not shown) is energized to rotate the roller 22 in a counter-clockwise direction driving the bottom card forward free of the hopper into the feed rollers 30 in the same manner as previously described. Thereafter, the solenoid 46 is
de—energized and member 40 and roller 22 move to the disengaged position under the urging of spring 44. As shown in Fig. 2c , by reversing the direction of rotation of the roller 22, the bottom card is driven along the feed path 12 clear of the hopper 14 into the feed rollers 30. Industrial Applicability and Advantages
The apparatus for feeding individual cards is particularly suitable for use in thermal printers which print ID cards.
Because of the bow of the bottom card when placed into the hopper, card feeding apparatus in accordance with this invention positively feeds individual cards without misfeeds.