US3586318A

US3586318A - Sheet registration and feeding

Info

Publication number: US3586318A
Application number: US868996A
Authority: US
Inventors: Segwald J Reckdahl; Donald W Folske
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1969-10-24
Filing date: 1969-10-24
Publication date: 1971-06-22
Anticipated expiration: 1988-06-22
Also published as: JPS5130799B1; GB1333237A; DE2055256A1; CA922327A

Abstract

A set of sheets in registered in a stack on a pin means and adjacent guide means. The sheets are fed seriatim from the stack by feed means operating with a predetermined force. The pin means have a semicircular cross-sectional configuration. Each sheet in the set contains a registration edge for registering each sheet with the guide means and an aperture for registering each sheet with the pin means. The aperture is positioned in a prescribed relationship to and closely adjacent the registration edge. The aperture edge and the registration edge define a holding strip of varying width. The narrowest portion of the holding strip defines a separation region of a predetermined width between the aperture and the registration edge. Portions of the aperture edge are shaped for registering each sheet with a pin means adjacent the separation region. Portions of the aperture edge in common with the holding strip and adjacent the registering portions of the aperture edge on opposite sides of the registering portions from the separation region define two clearance edges. The two clearance edges converge toward each other in a direction toward the registration edge and thereby enable the holding strip to deflect to concentrate tension in the separation region when the holding strip of a registered sheet is forced against the pin means. The two clearance edges are preferably straight edges. The feed means include feed legs which are positioned on each side of the pin means for engaging the outside registered sheet at positions adjacent the registration edge beyond each side of the aperture; and the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip for concentrating tension in the separation region when the holding strip is forced against the pin means by the feed legs feeding the registered and engaged sheet from the stack. The feed legs are also spaced apart by a predetermined distance for enabling the feeding of the engaged sheet from the stack; that is, the feed legs must be placed close enough together to cause sufficient force to be applied between the holding strip and the pin means to enable the separation of the holding strip upon the operation of the feed means. The feed means include means for engaging the feed legs with the registration edge of an outside registered sheet for enabling the feed legs to push against the engaged registration edge to feed the engaged sheet from a registered stack. The feed means also include means for applying a force to compress the stack for aligning the registration edge of the outside registered sheet with the feed legs to enable the engagement of the feed legs with the registration edge. The feed legs are variably disposed to the holding means in response to variations in the size of a stack; and the feed means include spring means for providing the force which is applied for compressing the stack of sheets. These spring means are operatively responsive to a variation in the disposition of the feed means in response to a reduction in the size of the stack for decreasing the provided applied compressive force as the size of the stack is reduced.

Description

United States Patent Primary Examiner-Joseph Wegbreit Attorney-Kinney, Alexander, Sell, Steldt & Delahunt ABSTRACT: A set of.sheets in registered in a stack on a pin means and adjacent guide means. The sheets. are fed seriatim from the stack by feed means operating with a predetermined force. The pin means have a semicircular cross-sectional configuration. Each sheet in the set contains a registration edge for registering each sheet with the guide means and an aperture for registering each sheet with the pin means. The aperture is positioned in a prescribed relationship to and closely adjacent the registration edge. The aperture edge and the registration edge define a holding strip of varying width. The narrowest portion of the holding strip defines a separation region of a predetermined width between the aperture and the registration edge Portions of the aperture edge are shaped for registering each sheet with a pin means adjacent the separation region. Portions otthe aperture edge in common with the holding strip and adjacent the registering portions of the aperture edge on opposite sides ofthe registering portions from the separation region define two clearance edgesv The two clearance edges converge toward each other in a direction toward the registration edge and thereby enable the holding strip to deflect to concentrate tension in the separation region when the holding strip of a registered sheet is forced against the pin means. The two clearance edges are preferably straight edges. The feed means include feed legs which are positioned on each side of the pin means for engaging the outside registered sheet at positions adjacent the registration edge beyond each side of the aperture; and the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip for concentrating tension in the separation region when the holding strip is forced against the pin means by the feed legs feeding the registered and engaged sheet from the stack. The feed legs are also spaced apart by a predetermined distance for enabling the feeding of the engaged sheet from the stack; that is, the feed legs must be placed close enough together to cause sufficient force to be applied between the holding strip and the pin means to enable the separation of the holding strip upon the operation of the feed means. The feed means include means for engaging the feed legs with the registration edge of an outside registered sheet for enabling the feed legs to push against the engaged registration edge to feed the engaged sheet from a registered stack. The feed means also include means for applying a force to compress the stack for aligning the registration edge of the outside registered sheet with the feed legs to enable the engagement of the feed legs with the registration edge. The feed legs are variably disposed to the holding means in response to variations in the size of a stack; and the feed means include spring means for providing the force which is applied for compressing the stack of sheets. These spring means are operatively responsive to a variation in the disposition of the feed means in response to a reduction in the size of the stack for decreasing the provided applied compressive force as the size of the stack is reduced.

SHEET REGISTRATION AND FEEDING CROSS-REFERENCE TO RELATED APPLICATION This application is related to the copending application filed by John L. Roche on Feb. 10, 1969, Ser. No. 798,016, and to the copending application filed by one of the present inventors, Segwald J. Reckdahl, on Oct. 24, i969, Ser. No. 869,002.

BACKGROUND OF THE INVENTION The present invention relates to sheet feeding and registration and is particularly directed to a combination wherein a stacked set of sheets is registered on a pin means in a given position, in which given position registration of each remaining sheet in the stack is maintained as sheets are fed seriatim from the stack.

A specific application of the present invention is with a test grading device, such as is described in U.S. Pat. application Ser. No. 798,016 by Roche, filed on Feb. 10, 1969, wherein a set of stacked answer sheets are held by pin means in a position for scanning of answer indication areas placed on each answer sheet, and wherein each scanned answer sheet is individually torn from said pin means for removal from the scanning position.

In accordance with the description of the test grading device set forth in the Roche application, a stack of answer sheets, each having a predetermined configuration of answer indication areas placed thereon in a predetermined relationship to a registration edge of the sheet, is placed on supporting means in a given position for the scanning of the answer indication areas of each sheet. This given position is defined by guide means such as bars which are disposed adjacent the supporting means. Once the stack of sheets is in the given position, a pin means such as a sharpened needlelike pin is driven through the stack in order to hold the sheets in the given position. The answer indication areas of the outside sheet in the stack are scanned and the answer indications which are sensed in the scanned answer indication areas are compared with answer indications sensed from corresponding answer indication areas of an answer key. From such comparisons, each answer sheet is scored. Following the scanning of each sheet,

the scanned sheet is engaged by removal means, such as feed means, which feed the scanned sheet from the pin, thereby removing the scanned sheet from the scanning position.

The predetermined configuration of answer indication areas is placed upon the answer sheet in a prescribed relationship to the registration edge of the sheet so that the scanning of the answer indication areas of the answer sheet is synchronized with the scanning of the corresponding answer indication areas of the answer key. The answer key has a fixed position in relation to the guide means and in relation to the stack holding position of the pin means. The degree to which each answer sheet ofa stack can be placed in a position corresponding with the position of the other sheets in the stack, or can be positioned for insuring that the scanning of the answer indication areas of each answer sheet is synchronized with the scanning of the corresponding answer indication areas of an answer key, is limited by human ability and diligence in uniformly stacking the sheets when placing them against the guide means and by the holding capability of the pin means.

Certain difficulties have arisen in feeding of the above described answer sheet ofthe prior art. For example, when the sheets are separated from the needlelike pin means, the tearing is ragged and there is an appreciable residue of debris resulting from the tearing. When larger pin means are used, multiple tearing of the sheets also results. Also, there is a tendency of the prior art answer sheets to either be double-fed or misfed from the given position upon operation of the feeding means.

in order to provide an answer sheet which can be registered for synchronized scanning in a test grading device and also be reliably fed from the holding means of the test grading device,

a novel set of answer sheets was-invented. This novel set of answer sheets is described in the copending U.S. Pat. application by one of the present inventors, Segwald J, Reckdahl, filed on even date herewith.

The feed means described in the aforementioned Roche application include two feed legs which are disposed for engaging the exposed surface of the outside sheet of a stack of registered sheets. The feed legs exert a downward pressure on the stack of registered sheets. The feed legs also include gripping pads for engaging the outside registered sheet. The feed legs are pivotally mounted to an axis which is above and to the rear of the stack of registered sheets in relation to the direction of travel of the feed legs. Therefore, when the feed means operate, the feed legs exert sufficient downward and forward pressure on the engaged outside registered sheet of the stack to tear it from the pin means. Upon the engaged sheet tearing from the pin means, the pivotally mounted feed legs pivot off the stack of answer sheets and the downward force is not transmitted to the remaining sheets in the stack. With this feeding device, however, there are limitations in the size of the paper stack since the downward force applied to the stack appreciably increases as the size of the stack is reduced. When using this feed means with a large stack of registered sheets, there may be either misfeeding at the top of the stack or double-feeding-at the bottom of the stack, or both.

Another problem is the accumulation of paper dust on the gripping pads after a certain number of sheets have been fed, thereby reducing the coefficient of friction between the gripping pads and the outside engaged registered sheet. As a result, misfeeding increases as this coefficient of friction is reduced, unless the gripping pads are periodically cleaned.

It is an object of the present invention to provide a sheet registration and feeding mechanism which, when combined with a set of sheets, such as a novel set of answer sheets described in the aforementioned copending application, provides registration of the sheets and reliable seriatim feeding of the sheets from a registered position.

It is desirable that the probability of double-feeding or misfeeding of the sheets be reduced.

it is also desirable that each sheet consistently tear in a defined separation region having a predetermined width, thereby minimizing the range of the predetermined feeding force. I

It is additionally desirable that the tearing of each sheet not be ragged since ragged tearing inhibits uniform stacking of fed sheets for scanning of the opposite surface thereof with a second registration edge positioned against the guide means.

It is further desirable that the residue of debris resulting from the tearing be appreciably minimized since the debris tends to inhibit consistent feeding of the remaining sheets.

SUMMARY OF THE INVENTION The present invention provides a sheet registration and feeding mechanism in and for combination with a set of sheets, such as the answer sheets which are the subject of the aforementioned copending U.S. Pat. application by Reckdahl. Each answer sheet in the set contains an aperture which is positioned in a prescribed relationship to and closely adjacent a registration edge. The aperture edge and the registration edge define a holding strip of varying width between the aperture and the registration edge, wherein the narrowest portion of the holding strip defines a separation region of a predetermined width between the aperture and the registration edge. The narrowest portion of the holding strip defines the separation region. Portions of the aperture in common with the holding strip and adjacent the registering portions of the aperture edge on opposite sides of the registering portions from the separation region define two clearance edges. The two clearance edges converge toward each other in a direction toward the registration edge for enabling the holding strip to deflect to concentrate tension in the separation region when the holding strip of a registered sheet is forced against the pin means.

In accordance with the disclosure of the aforementioned copending Reckdahl application, it has been observed that when sheets having the aforesaid limitations are fed from pin means with a predetermined force, reliability of feeding is increased, each fed sheet is consistently and more cleanly torn in the separation region, and the residue of debris is appreciably reduced. Concentration of tension in the separation region is increased by providing that the two clearance edges be straight edges.

It is preferred that the registration edge is a straight edge and that the aperture is symmetrical about an axis perpendicular to the registration edge.

The reliability with which the aforesaid sheets may be registered and fed may be further increased by providing certain combinations of various species of answer sheets, pin means and feed means in accordance with the present invention. Combining the sheets with the sheet registration and feeding apparatus according to the present invention improves reliability in sheet registration and feeding by providing certain features in the pin means and feed means which are used in combination with a stacked set of sheets such as the set of answer sheets described in the aforementioned copending Reckdahl application. Such reliability is also improved by providing certain additional features in the set of sheets in relation to the particular pin means and feed means with which the sheets are combined. The sheets may include sheets other than answer sheets.

in accordance with the present invention, the pin means are shaped for registration with the registering portions of the aperture edge of each sheet, and the feed means are positioned for engaging the outside sheet of a registered stack of sheets and for feeding the engaged sheet from the registered stack with a predetermined force. The feed means include feed legs which are positioned on each side of the pin means for engaging the outside registered sheet at positions adjacent the registration edge beyond each side of the aperture; and the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip to concentrate tension in the separation region when the holding strip is forced against the pin means by the feed legs feeding the registered and engaged sheet from the stack. The feed legs are also spaced apart by a predetermined distance for enabling the feeding of the engaged sheet from the stack; that is, the feed legs must be placed close enough together to cause sufficient force to be applied between the holding strip and the pin means to enable the separation of the holding strip upon the operation of the feed means. If the feed legs are not placed close enough together to provide this sufficient force relationship between the holding strip and the pin means, the feed legs may ride over or bend the registered sheet rather than feed the registered sheet from the given position.

The feed means on the feed legs include means for engaging the feed legs with the registration edge of an outside registered sheet for enabling the feed legs to push against the engaged registration edge to feed the engaged sheet from a registered stack and for applying a force to compress the stack for aligning the registration edge of the outside registered sheet with the feed legs to enable the engagement of the feed legs with the registration edge. Absent the compression of the stack, the registration edge ofa sheet may be slightly bent so that the registration edge is not aligned for engagement with both feed legs.

The feed legs are variably disposed to the holding means in response to variations in the size of a stack; and the feed means include spring means positioned for providing the force which is applied for compressing the stack of sheets. These spring means are operatively responsive to a variation in the disposition of the feed legs in response to a reduction in the size of the stack for decreasing the provided applied compres sive force as the size of the stack is reduced.

In the embodiment wherein each sheet is of a predetermined thickness, each feed leg includes a step for applying the force for compressing the stack and for engaging the registration edge of the outside registered sheet. Each step comprises a plate having a surface disposed for pressing against the exposed surface of the outside registered sheet adjacent the registration edge thereof, for applying the compressive force, and a riser joined to the pressing surface of the plate, for engaging the registration edge of the outside registered sheet and for pushing against the registration edge to feed the engaged outside registered sheet from the stack upon the operation of the feeding means. The thickness of the step provided by the riser is not greater than the thickness of each sheet. The thickness of the step provided by the riser is defined as the distance between the plate and the position where the riser contacts the registration edge of the outside registered sheet.

it is preferred that the riser have a V-shaped edge for pushing against the registration edge of the outside registered sheet. The surface of the riser which is joined to the pressing surface of the plate is disposed at an acute angle to the pressing surface and the thickness of the step provided by the riser is less than the thickness of each step. However, the thickness of the riser is slightly greater than the thickness of each sheet. The thickness of the riser is defined as the distance between the ends ofthe arms of the V".

In one preferred embodiment, the registration edge of each sheet is smooth for enabling penetration of the registration edge of the outside registered sheet by the V-shaped riser edge and for enabling holding by the registration edge of the penetrating riser edge. A smooth edge is defined as the type of edge obtained when cutting paper with a sharpened guillotine cutter or sharpened slitter cutter in contrast to the type of edge obtained by cutting paper with a dull slitter cutter or a dull guillotine cutter.

ln a preferred embodiment, wherein each sheet is ofa given width between the aperture and the edge opposite the registration edge, means are provided for maintaining the fed sheets in the sequence in which they were originally placed in stacked registration on the pin means. The sequence maintaining means comprise a stop disposed in relation to the pin means for stopping movement of a fed sheet, wherein the distance between the stop and the pin means is less than approximately twice the given width, whereby the registration edge ofa fed sheet rests on and overlapping the opposite edge of an outside registered sheet When the feed legs including the above-described steps are used in combination with the above-described sequence-maintaining means, the force provided by the plate to a sheet during feeding prevents buckling of the sheet near the registration edge thereof.

Again referring to the set of sheets for each sheet in a set, it is preferred that the two clearance edges are straight edges; that the pin means have a curved holding surface and that the pin means is disposed for registering the curved holding surface with the two straight edges. It is also preferred that the aperture of each sheet is an isosceles triangle with the vertex adjacent the separation region and with the base parallel to the registration edge; that the pin means have a semicircular holding surface and that the pin means is disposed for registering the flat surface of the pin means with the base of the aperture.

In a preferred embodiment, the dimensions of the registering portions of the aperture edge are slightly larger than the corresponding dimensions of the pin means, thereby preventing a snug registration; and the feed legs are disposed for dragging across the outside registered sheet during an interval between the feeding of the fed sheet and the engagement of the next outside registered sheet, which dragging provides a small opening between the pin means and the holding strip of the outside registered sheet.

A snug registration is undesirable for the following reasons. A snug registration makes the registering of the sheets on the pin means more difficult; a snug registration impedes compression of the sheets for aligning the registration edge of the sheets with each step of the feed legs; and a snug registration increases the likelihood of tearing the edges of the aperture while registering the sheets on the pin means.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates in perspective a sheet registration and feeding apparatus in combination with a set of sheets.

FIG. 2 illustrates a sheet of a set of answer sheets for use in the combination illustrated in FIG. 1.

FIG. 3 is another perspective view of the sheet registration and feeding apparatus and sheet set combination illustrated in FIG. 1.

FIG. 4 is a top view of the feed means shown in the sheet registration and feeding apparatus illustrated in FIGS. 11 and 3.

FIG. 5 is a sectional view taken along and in the direction of line 5-5 of FIG. 4, which view illustrates a feed leg with a step attached thereto for compressing a set of stacked registered answer sheets and for engaging the outside sheet of the registered stack.

FIG. 6 is a perspective view of an embodiment of feed legs for engaging and feeding the outside sheet of the registered stack, which embodiment is alternative to that shown in FIGS. 1 and 35.

FIGS. 7a7e illustrate various alternative embodiments of the registration edge, aperture and holding strip of a sheet for use in the combination of the present invention. Pin means for registration with the illustrated apertures are shown by dashed line.

DESCRIPTION OF THE PREFERRED EMBODIMENT The combination of a set of sheets and a sheet registration and feeding apparatus according to the present invention is illustrated in FIG. 1. A stacked set of sheets 30 is shown in combination with the feed means 32 and the holding means 34.

FIG. 2 illustrates a sheet of a set for use in the combination shown in FIG. 1. Although an answer sheet is illustrated in FIG. 2, the set is not necessarily a set of answer sheets.

The answer sheet contains an aperture 12 positioned in a prescribed relationship to and closely adjacent the registration edge 10. The pin means 14 are shown by the dashed line in FIG. 2. The aperture edge 13 and the registration edge 10 define a holding strip 16 of varying width between the aperture l2 and the registration edge 10. The narrowest portion of the holding strip 16 defines a separation region 18 of a predetermined width between the aperture 12 and the registration edge 10. The aperture 12 is symmetrical about a line which is perpendicular to the registration edge 10. The separation region [8 lies along this line 20.

It is seen that portions of the aperture edge 13 are shaped for registering the answer sheet with the pin means 14 adjacent the separation region 18. Two portions of the aperture edge 13 in common with the holding strip 16 and adjacent the registering portions 21 on opposite sides of the registering portions 21 from the separation region 18 define two clearance edges 22. The two clearance edges 22 converge toward each other in a direction toward the registration edge 10 and thereby enable the holding strip 16 to deflect to concentrate tension in the separation region 18 when the holding strip 16 is forced against the pin means 14.

Preferably, the clearance edges 22 are straight edges and the aperture 12 is centered along the registration edge 10.

In the preferred embodiment, the set of sheets may be registered with a pin means 14, such as a pin having a semicircular cross-sectional dimension, wherein the diameter is 0.25 inches (approximately 6.4 mm.) and be fed by feed means which feed the answer sheets with a predetermined force which is in the range of 20 to ounces (approximately 5.6 to 7.0 ncwtons). In this preferred embodiment, each sheet is a paper sheet approximately 4 mils. (approximately 0.1 mm.) thick in which the aperture 12 is an isosceles triangle having a base 0.5 inches (approximately 1.3 cm.) in length parallel to the registration edge 11), and having a separation region 18 of a predetermined width of 22 mils. (approximately 0.56 mm.) between the triangle vertex and the registration edge 10. The sheet is approximately 1 1 inches (approximately 28 cm.) along the registration edge 10 and has a given width between the aperture 12 and the edge 24 opposite the registration edge 10 of approximately 4 inches (approximately 10 cm.). The height of the triangle is 0.173 inches (approximately 4.4 mm.). DATA" brand OCR Bond 200 paper available from the International Paper company New York, N.Y., is preferred, and all sheets in a set preferably have the fiber running in the same direction in relation to the registration edge. The paper has an average smoothness of 112 Sheffield units.

In one preferred embodiment, answer indication areas are provided on each surface of the sheet, and

apertures

12 and 26 adjacent registration edges 10 and 24, respectively, are provided, thereby doubling the question capacity of each answer sheet.

Answer indications are shown in various answer indication areas of the answer sheet of FIG. 2.

A stacked set of sheets 30 is shown in combination with the feed means 32 and holding means 34 in FIGS. 1 and 35. The holding means 34 comprise pin means 36, a table 38 and guide means such as the bars 40, for receiving and supporting the set of sheets 30 in stacked registration with the pin means 36. The pin means 36 prevent lateral movement of the sheets and the bars 40 in combination with the pin means 36 prevent rotational movement. The table 38 is slidably mounted on the frame 41 so that the pin means 36 can be pulled out from under the feed means 32 when a set of sheets is registered on the pin means 36. The feed means 32 comprise feed legs 42 and a spring 44 for providing a predetermined force to move the feed legs 42 for feeding sheets from the stack 30. The feed legs 42 are positioned on each side of the pin means 36 at positions adjacent the registration edge 10 beyond each side of the aperture 12. The feed legs 42 are attached by supporting

members

46, 48 and 50 to a baseplate (not shown) as described in the aforementioned U.S. Pat. application by Roche. This baseplate is slidably mounted in a holder (not shown) which is positioned in a stationary relationship to the frame 41 supporting the holding means 34. The apertures 52 in the supporting members 50 are for coupling the feed means 32 to the baseplate. The baseplate and the feed means 32 may be slidably positioned in either a cocked or a forward position. The feed means 32 are shown in the cocked position in FIGS. 1 and 3-5. The feed legs 42 when operated move from this cocked position to a forward position for removing a sheet such as fed sheet 54 from the registered stack 30 to a stopped position, such as that in which the fed sheet 54 is shown.

The feed means 32 include means, such as the steps 56 for engaging the feed legs 42 with the registration edge 10 of an outside registered sheet 58 of the stack 30 for enabling the feed legs 42 to push against the engaged outside registered sheet 58 to feed the engaged sheet 58 from the stack 30. The steps 56 also are means by which the feed means 32 apply a force to compress the stack 30 for aligning the registration edge 10 of the outside sheet 58 with the feed legs 42 to enable the feed legs 42 to engage the registration edge 10.

The table 38 includes a bench 59 positioned beneath the cocked position of the feed legs 42. The steps 56 rest on the bench 59 when no sheets are registered on the pin means 36.

Each step 56 comprises a plate 60 and a riser 62. The plate 60 is disposed for pressing against the exposed surface 64 of the outside registered sheet 58. The plate 60 is also disposed adjacent the registration edge 10 of the outside registered sheet 58 to apply the force for compressing the stack 30. This applied force is provided by spring means such as the spring 66. The riser 62 is joined to the pressing surface 68 of the plate 60 for engaging the registration edge 10 of the outside registered sheet 58 and for pushing against the registration edge 10 to feed an engaged outside registered sheet 58 from the stack 30 upon the operation of the feeding means 32 Each sheet in the stack 30 is of a predetermined thickness and the thickness of the step provided by the riser 62 is not greater than the thickness of each sheet of stack 30. The riser 62 has a V-shaped edge for pushing against the registration edge 10 of the outside registered sheet 58. It is seen in FIG. that the surface 70 of the riser 62 which is joined to the pressing surface 68 of the plate 60 is disposed at an acute angle to the pressing surface 68. The thickness of the step provided by the riser 62 is the distance between the point of the V" where the riser engages the registration edge and the pressing surface 68 of the plate 60, the thickness of the riser 62, however, being the distance between the ends of the arms of the V. The thickness of the riser 62 is slightly greater than the thickness of each sheet of the stack 30, thereby alleviating the frictional drag between the outside sheet 58 and the second sheet 78 when the outside sheet 58 is fed and the riser 62 rides on the second sheet 78. The registration edge 10 of each sheet is preferably smooth for enabling the V-shaped edge of the riser 62 to penetrate the registration edge 10 for enabling the registration edge 10 to hold the penetrating edge of the riser 62.

An alternative embodiment of the steps 56 is shown in FIG. 6. In this alternative embodiment, the steps 72 are also attached to the feed legs 42. However, in this embodiment the riser edge is a vertical surface provided by member 74 and the plate 76 is disposed at a slight angle to the horizontal surface of the outside registered sheet 58 of the stack 30.

The force provided by the spring means 66 is transmitted to the feed legs 42 by the supporting member 48. Referring to FIG. I. it is seen that the spring 66 is fastened to the supporting member 50 by fastening member 80. The other end of the spring 66 is fastened to an extension 82 of the supporting member 48 which passes through an aperture 84 in the supporting member 50. Extension 82 is loosely pivotally connected to supporting member 50 by means of pin 85. The feed legs 42 are thereby self-leveling so that each feed leg 42 can engage the registration edge 10 of the outside registered sheet 58. It is seen by this combination of spring means 66, supporting member 48 and feed legs 42 that the feed legs 42 are variably disposed to the holding means 34 in response to variations in the size of the registered stack 30 and that the spring means 66 are operatively responsive to a variation in the disposition of the feed legs 42 in response to a reduction in size of the registered stack 30 for decreasing the provided applied force as the size of the stack 30 is reduced.

The feed legs 42 are centered about the pin means 36 by supporting member 46 and the rails 86.

Means are also provided for maintained fed sheets such as sheet 54 in the sequence in which stacked in the registered stack 30. The sequence-maintaining means comprise a stop 88 which is disposed on the holding means 34 for stopping movement of each fed sheet 54. Each sheet of the stack 30 is of a given width between the aperture 12 and the edge 24 opposite the registration edge 10. The distance between the stop 88 and the pin means 36 is less than approximately twice the given width between the aperture 12 and the opposite edge 24. By so placing the stop 88 at this predetermined distance from the pin means 36, the registration edge 10 of a fed sheet rests on and overlapping the opposite edge 24 ofthe outside registered sheet 58 of the stack 30. Therefore, as each sheet 54 is fed from the stack 30, it is positioned beneath the previously fed sheets 54 and the fed sheets are maintained in the same sequence as in which they were originally stacked.

The feed force of the feed means 32 is greater than the force required to separate the sheet at the separation region 18 plus the frictional force provided upon operation of the feed means 32 between the outside registered sheet 58 and the second registered sheet 78 due to the pressure provided by the plates 60.

When the sequence-maintaining means 88 is included the feed force of the feed means 32 is greater than the force required to separate the sheets at the separation region 18 plus the frictional force provided upon operation of the feed means 32 between the outside registered sheet 58 and the second registered sheet 78 due to the pressure provided by the plates 60 plus the frictional resistance force due to the weight of the stack of the removed sheets 54 inresting upon the sheets remaining in the stack 30.

Also, the coefficient of friction of the table 38 is preferably as large as the coefficient of friction of each sheet in the stack 30.

The stiffness of each sheet is sufficient to prevent buckling of the bottom sheet of the stack 30 ofa predetermined quantity of sheets when fed from the pin means 36 beneath the stack of fed sheets 54.

For seriatim feeding of sheets having the dimensions set forth for a set of answer sheets such as is illustrated in FIG. 2, the centers of the feed legs 42 are spaced apart by from 0.69 to 0.81 inches (approximately 1.8 to 2.1 cm.). The plates are each 0.38 inches (approximately 9.7 mm.) (parallel to the registration edge 10) by 0.5 inches (approximately 1.3 cm.) and 0.06 inches (approximately 1.5 mm.) thick. The spring 44, when in a cocked position, provides a force in the range of from 25 to 30 ounces (7.0 to 8.3 newtons). When the feed means are operated, the predetermined feeding force provided at the feed legs 42 from the spring 44 is in the range of from 20 to 25 ounces (5.6 to 7.0 newtons). The compressive force applied at the plates 60, which force is provided by the spring 66, is in the range of from 5 to 9 ounces 1.4 to 2.5 new tons). The stiffness of the paper sheets is approximately 2.05 Taber stiffness units. The foregoing dimensions are for the embodiment including the sequence-maintaining means.

It has been found that various combinations of registration edge 10 configurations, aperture 12 configurations and pin means 14 configurations according to the present invention provide reliable sheet feeding. These various combinations are illustrated in FIG. 7. In all five configurations shown, as well as in the configurations shown in FIG. 2, the width of the separation region 18 between the aperture 12 and the registration edge 10 is a predetermined width. The registration edge may include a rectangular notch as shown in FIG. 7a a curved groove 92 as shown in FIGS. 7b and 7d, or a slit 94 as shown in FIG. 7c. In the combination shown in FIG. 70, the predetermined width of the separation region 18 is the distance between the aperture 12 and the end of the slit 94 nearest the the aperture 12.

The pin means 14 may be semicircular as illustrated in FIGS. 2, 7a, 7b or 7d, or round, as illustrated in FIGS. 70 and 7e. Other pin shapes may also be used, however, the illustrated shapes are preferred.

The combination of a pin having a curved surface with an aperture having straight edges such as illustrated in FIGS. 2, 7a, 7b and 7c was found to provide the best combination of reliable feeding and consistent clean separation in the separation region. Providing curved aperture edges adjacent the holding strip 16 in combination with the pin having a curved surface such as is illustrated in FIGS. 7d and 7e also produced reliable feeding, however, the tears for the configuration illustrated in FIG. 7d, while consistently in the separation region, were sometimes ragged. The registration provided by the combination of FIG. 7d is less precise than provided by the other combinations shown, but is acceptable when synchronization tolerances permit less precise registration.

The significant feature for all combinations of aperture 12 and pin means 14 is that portions of the edge of the aperture 12 be shaped for registering with the pin means 14 to prevent lateral movement of the sheet and that clearance edges 22 be provided to enable the holding strip 16 to deflect to concentrate tension in the separation region when the pin means 14 is forced against the holding strip 16 upon the operation of the feed means 32. Reliable feeding and clean, consistent separation in the separation region is also improved by providing that the aperture 12 be symmetrical about an axis 20 which is perpendicular to the registration edge 10.

We claim:

I. In combination:

a set of sheets adapted for stacked registration with a pin apply a said force; and a riser joined to the pressing surmeans and for seriatim feeding from a said stack, each sheet including a registration edge and containing an aperture which is positioned in a prescribed relationship face of the plate for engaging the registration edge of a said outside registered sheet and for pushing against the registration edge to feed a said engaged outside registered to and closely adjacent the registration edge, the aperture sheet from a said stack upon said feeding by the feed edge and the registration edge defining a holding strip of means, wherein the thickness of the step provided by the varying width between the ap rtur nd th r i ati riser is not greater than the thickness ofeach sheet.

edge; the narrowest portion ofthe holding strip defining a 5. A sheet registration and feeding combination according separation region of a predetermined width between the to Claim 4, further Characterized y the feature that aperture and the registration edge; portions of the aperthe riser has p edge for Pushing against the regisw d b i h d f registering h sheet with a tration edge of a said outside registered sheet, wherein id i means dj h Separation i two the surface of the riser which is joined to the pressing surtions of the aperture edge in common with the holding face the Plate is dispose? at an acute angle to the strip and adjacent the registering portions of the aperture Pressmg Surface, and wherem the thlckhess of the step provided by the riser is less than the thickness of each sheet.

6. A sheet registration and feeding combination according to claim 5, further characterized by the feature that the registration edge of each sheet is smooth for enabling penetration of the registration edge of a said outside rcgistered sheet by the riser edge and for enabling holding by the registration edge of a said penetrating riser edge.

7. A sheet registration and feeding combination according to claim 5, further characterized by the feature that the thickness of the riser is slightly greater than the thickness of each sheet.

8. A sheet registration and feeding combination according to claim 1, wherein each sheet is of a given width between the aperture and the edge opposite the registration edge, further characterized by means for maintaining said fed sheet in the sequence in which stacked, comprising a stop disposed on the holding means for stopping move- 35 ment of a said fed sheet, wherein the distance between the stop and the pin means is less than approximately twice the given width, whereby the registration edge of a said fed sheet rests on the opposite edge of a said outside registered sheet. I

9. A sheet registration and feeding combination according to claim 8, further characterized by the feature that the feed means include means for engaging the feed legs with the registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning the registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registra- 50 tion edge;

each sheet is ofa predetermined thickness; and each feed leg includes a step for applying a said force to compress a said stack and for engaging the registration edge of a said outside registered sheet, wherein each step 55 comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent the registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging the registration edge of a said outside registered sheet and for pushing against the edge on opposite sides of the registering portions from the separation region defining two clearance edges, which two clearance edges converge toward each other in a direction toward the registration edge for enabling the holding strip to deflect to concentrate tension in the separation region when the holding strip of a said registered sheet is forced against a said pin means; and

a sheet registration and feeding apparatus comprising holding means for receiving and supporting the set of sheets in said stacked registration including pin means shaped for registration with the registering portions of the aperture edge of each sheet of the set, and guide means disposed relative to the pin means for registration with the registration edge of each said stacked sheet; and

feed means positioned for engaging the outside sheet of a said registered stack, and for feeding a said engaged sheet from a said registered stack with a predetermined force, which feed means include feed legs positioned on each side of the pin means for engaging a said outside registered sheet at positions adjacent the registration edge beyond each side of the aperture, wherein the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip for concentrating tension in the separation region when the holding strip of a said registered and engaged sheet is forced against the pin means by the feed means feeding a said registered and engaged sheet from a said stack. and for enabling the feeding ofa said engaged sheet from a said stack.

2. A sheet registration and feeding combination according to claim I, further characterized by the feature that the feed means include means for engaging the feed legs with the registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning the registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge.

3. A sheet registration and feeding combination according to claim 2, further characterized by the feature that the feed legs are variably disposed to the holding means in response to variations in the size of a said stack; and the feed means include spring means for providing a said applied force, which spring means are operatively responsive to a variation in the disposition of the feed legs in response to a reduction in the size of a said stack, for decreasing said provided applied force as the size of a said registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the stack is reduced.

4. A sheet registration and feeding combination according to claim 2, further characterized by the feature that each sheet is ofa predetermined thickness;

each feed leg includes a step for applying a said force to compress a said stack and for engaging the registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent the registration edge of a said outside registered sheet to riser is not greater than the thickness of each sheet; whereby a said provided force is applied by the plate to a said fed sheet during said feeding for preventing buckling near the registration edge of a said fed sheet. 10. A sheet registration and feeding combination according to claim 1, further characterized by the feature that in each sheet the two clearance edges are straight edges;

and the pin means has a curved holding surface and is disposed for registration of the curved surface with said two straight edges of a said sheet.

1]. A sheet registration and feeding combination according to claim I, further characterized by the feature that in each sheet the aperture is an isosceles triangle with the vertex adjacent the separation region and the base parallel to the registration edge; and

the pin means has a semicircular holding surface for registration with a said sheet, wherein the pin means is disposed for registration of the flat surface of the pin means with the base ofthe aperture of a said sheet.

12. A sheet registration and feeding combination according to claim 1, further characterized by the feature that the dimensions defined by the registering portions of the aperture edge are slightly larger than the corresponding dimensions of the pin means for preventing a snug registration.

13. A sheet registration and feeding combination according to claim 12, further characterized by the feature that the feed legs are disposed for dragging across a said outside registered sheet during an interval between the feeding of a fed sheet and the engagement of a said outside registered sheet, which dragging provides a small opening between the pin means and the holding strip of a said outside registered sheet.

14. A sheet registration and feeding apparatus for registering and feeding a set of sheets which is adapted for stacked registration with a pin means and for seriatim feeding from a said stack, each said sheet including a registration edge and containing an aperture which is positioned in a prescribed relationship to the answer indication areas, and is positioned in a prescribed relationship to and closely adjacent a said registration edge, a said aperture edge and a said registration edge defining a holding strip of varying width between a said aperture and a said registration edge; the narrowest portion of a said holding strip defining a separation region of a predetermined width between a said aperture and a said registration edge; portions of a said aperture edge being shaped for registering each sheet with a said pin means adjacent a said separation region; two portions ofa said aperture edge in common with a said holding strip and adjacent said registering portions of a said aperture edge on opposite sides of said registering portions from a said separation region defining two clearance edges, which two clearance edges converge toward each other in a direction toward a said registration edge for enabling a said holding strip to deflect to concentrate tension in a said separation region when a said holding strip of a said registered sheet is forced against a said pin means, comprising holding means for receiving and supporting a said set of sheets in said stacked registration including pin means shaped for registration with said registering portions of a said aperture edge of each sheet of a said set, and guide means disposed relative to the pin means for registration with a said registration edge of each said stacked sheet; and

feed means positioned for engaging the outside sheet of a said registered stack, and for feeding a said engaged sheet form a said registered stack with a predetermined force, which feed means include feed legs positioned on each side of the pin means for engaging a said outside registered sheet at positions adjacent a said registration edge beyond each side of a said aperture, wherein the feed legs are spaced apart by a predetermined distance for causing deflection of a said holding strip for concentrating tension in a said separation region when a said holding strip of a said registered and engaged sheet is forced against the pin means by the feed means feeding a said registered and engaged sheet from a said stack, and for enabling the feeding of a said engaged sheet from a said stack.

15. A sheet registration and feeding combination according to claim 14, further characterized by the feature that the feed means include means for engaging the feed legs with a said registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning a said registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge. I

16. A sheet registration and feeding combination according to claim 15, further characterized by the feature that the feed legs are variably disposed to the holding means in response to variations in the size of a said stack; and the feed means include spring means for providing a said applied force, which spring means are operatively responsive to a variation in the disposition of the feed legs in response to a reduction in the size of a said stack, for decreasing said provided applied force as the size ofa said stack is reduced.

17. A sheet registration and feeding combination according to claim 15, wherein each said sheet is of a predetermined thickness; further characterized by the feature that each feed leg includes a step for applying a said force to compress a said stack and for engaging a said registration edge ofa said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the surface of a said outside registered sheet adjacent a said registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging a said registration edge of a said outside registered sheet and for pushing against a said registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than a said thickness of each said sheet.

18. A sheet registration and feeding combination according to claim 17, further characterized by the feature that the riser has a V-shaped edge for pushing against a said registration edge of a said outside registered sheet, wherein the surface of the riser which is joined to the pressing surface of the plate is disposed at an acute angle to the pressing surface, and wherein the thickness of the step provided by the riser is less than the thickness of each said sheet.

19. A sheet registration and feeding combination according toclaim 18, further characterized by the feature that the thickness of the riser is slightly greater than the thickness of each said sheet.

20. A sheet registration and feeding combination according to claim 14, wherein each said sheet is of a given width between a said aperture and the edge opposite a said registration edge, further characterized by means for maintaining said fed sheets in the sequence in which stacked, comprising a stop disposed on the holding means for stopping movement of a said fed sheet, wherein the distance between the stop and the pin means is less than approximately twice a said given width, whereby a said registration edge of a said fed sheet rests on a said opposite edge of a said outside registered sheet.

21. A sheet registration and feeding combination according to claim 20, wherein each said sheet is of a predetermined thickness, further characterized by the feature that the feed means include means for engaging the feed legs with a said registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning a said registration edge ofa said outside registered sheet with the feed legs to enable said engagement with a said registration edge; and

each feed leg includes a step for applying a said force to compress a said stack and for engaging a said registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent a said registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging a said registration edge of a said outside registered sheet and for pushing against a said registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than a said thickness of each sheet;

whereby a said provided force is applied by the plate to a said fed sheet during said feeding for preventing buckling near a said registration edge of a said fed sheet.

22. A sheet registration and feeding combination according to claim 14, wherein in each said sheet said two clearance edges are straight edges, further characterized by the feature that the pin means has a curved holding surface and is disposed for registration of the curved surface with said two straight edges of a said sheet.

23. A sheet registration and feeding combination according to claim 13, wherein in each said sheet a said aperture is an isosceles triangle with the vertex adjacent a said separation region and the base parallel to a said registration edge, further characterized by the feature that the pin means has a semicircular holding surface for registration with a said sheet, wherein the pin means is disposed for registration of the flat surface of the pin means with a said base ofa said aperture ofa said sheet. 24. A sheet registration and feeding combination according to claim 14, wherein the dimensions defined by said registering portions of a said aperture edge is slightly larger than the corresponding dimensions of the pin means for preventing a snug registration, further characterized by the feature that the feed legs are disposed for dragging across a said outside registered sheet during an interval between the feeding of a fed sheet and the engagement of said outside registered sheet, which dragging provides a small opening between the pin means and a said holding strip ofa said outside registered sheet.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,586 318 Dated June 22 1971 Inventor(s) Segwald J. Reckdahl 8: Donald W. Folske It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Specification:

Column 6, line 9, change "200" to 20# Column 7, line 8, change "maintained" to maintaining Signed and sealed this 2nd day of November 1 971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORM po-aoso (Io-s9] USCQMWDC 60375.?

R U 5 GOVERNMENT PRINTING OFFICE 1 1909 O-L=5G-3 l

Claims

1. In combination: a set of sheets adapted for stacked registration with a pin means and for seriatim feeding from a said stack, each sheet including a registration edge and containing an aperture which is positioned in a prescribed relationship to and closely adjacent the registration edge, the aperture edge and the registration edge defining a holding strip of varying width between the aperture and the registration edge; the narrowest portion of the holding strip defining a separation region of a predetermined width between the aperture and the registration edge; portions of the aperture edge being shaped for registering each sheet with a said pin means adjacent the separation region; two portions of the aperture edge in common with the holding strip and adjacent the registering portions of the aperture edge on opposite sides of the registering portions from the separation region defining two clearance edges, which two clearance edges converge toward each other in a direction toward the registration edge for enabling the holding strip to deflect to concentrate tension in the separation region when the holding strip of a said registered sheet is forced against a said pin means; and a sheet registration and feeding apparatus comprising holding means for receiving and supporting the set of sheets in said stacked registration including pin means shaped for registration with the registering portions of the aperture edge of each sheet of the set, and guide means disposed relative to the pin means for registration with the registration edge of each said stacked sheet; and feed means positioned for engaging the outside sheet of a said registered stack, and for feeding a said engaged sheet from a said registered stack with a predetermined force, which feed means include feed legs positioned on each side of the pin means for engaging a said outside registered sheet at positions adjacent the registration edge beyond each side of the aperture, wherein the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip for concentrating tension in the separation region when the holding strip of a said registered and engaged sheet is forced against the pin means by the feed means feeding a said registered and engaged sheet from a said stack, and for enabling the feeding of a said engaged sheet from a said stack.

2. A sheet registration and feeding combination according to claim 1, further characterized by the feature that the feed means include means for engaging the feed legs with the registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning the registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge.

3. A sheet registration and feeding combination according to claim 2, further characterized by the feature that the feed legs are variably disposed to the holding means in response to variations in the size of a said stack; and the feed means include spring means for providing a said applied force, which spring means are operatively responsive to a variation in the disposition of the feed legs in response to a reduction in the size of a said stack, for decreasing said provided applied force as the size of a said stack is reduced.

4. A sheet registration and feeding combination according to claim 2, further characterized by the feature that each sheet is of a predetermined thickness; each feed leg includes a step for applying a said force to compress a said stack and for engaging the registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent the registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging the registration edge of a said outside registered sheet and for pushing against the registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than the thickness of each sheet.

5. A sheet registration and feeding combination according to claim 4, further characterized by the feature that the riser has a V-shaped edge for pushing against the registration edge of a said outside registered sheet, wherein the surface of the riser which is joined to the pressing surface of the plate is disposed at an acute angle to the pressing surface, and wherein the thickness of the step provided by the riser is less than the thickness of each sheet.

6. A sheet registration and feeding combination according to claim 5, further characterized by the feature that the registration edge of each sheet is smooth for enabling penetration of the registration edge of a said outside registered sheet by the riser edge and for enabling holding by the registration edge of a said penetrating riser edge.

8. A sheet registration and feeding combination according to claim 1, wherein each sheet is of a given width between the aperture and the edge opposite the registration edge, further characterized by means for maintaining said fed sheet in the sequence in which stacked, comprising a stop disposed on the holding means for stopping movement of a said fed sheet, wherein the distance between the stop and the pin means is less than approximately twice the given width, whereby the registration edge of a said fed sheet rests on the opposite edge of a said outside registered sheet.

9. A sheet registration and feeding combination according to claim 8, further characterized by the feature that the feed means include means for engaging the feed legs with the registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning the registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge; each sheet is of a predeterMined thickness; and each feed leg includes a step for applying a said force to compress a said stack and for engaging the registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent the registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging the registration edge of a said outside registered sheet and for pushing against the registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than the thickness of each sheet; whereby a said provided force is applied by the plate to a said fed sheet during said feeding for preventing buckling near the registration edge of a said fed sheet.

10. A sheet registration and feeding combination according to claim 1, further characterized by the feature that in each sheet the two clearance edges are straight edges; and the pin means has a curved holding surface and is disposed for registration of the curved surface with said two straight edges of a said sheet.

11. A sheet registration and feeding combination according to claim 1, further characterized by the feature that in each sheet the aperture is an isosceles triangle with the vertex adjacent the separation region and the base parallel to the registration edge; and the pin means has a semicircular holding surface for registration with a said sheet, wherein the pin means is disposed for registration of the flat surface of the pin means with the base of the aperture of a said sheet.

14. A sheet registration and feeding apparatus for registering and feeding a set of sheets which is adapted for stacked registration with a pin means and for seriatim feeding from a said stack, each said sheet including a registration edge and containing an aperture which is positioned in a prescribed relationship to the answer indication areas, and is positioned in a prescribed relationship to and closely adjacent a said registration edge, a said aperture edge and a said registration edge defining a holding strip of varying width between a said aperture and a said registration edge; the narrowest portion of a said holding strip defining a separation region of a predetermined width between a said aperture and a said registration edge; portions of a said aperture edge being shaped for registering each sheet with a said pin means adjacent a said separation region; two portions of a said aperture edge in common with a said holding strip and adjacent said registering portions of a said aperture edge on opposite sides of said registering portions from a said separation region defining two clearance edges, which two clearance edges converge toward each other in a direction toward a said registration edge for enabling a said holding strip to deflect to concentrate tension in a said separation region when a said holding strip of a said registered sheet is forced against a said pin means, comprising holding means for receiving and supporting a said set of sheets in said stacked registration including pin meaNs shaped for registration with said registering portions of a said aperture edge of each sheet of a said set, and guide means disposed relative to the pin means for registration with a said registration edge of each said stacked sheet; and feed means positioned for engaging the outside sheet of a said registered stack, and for feeding a said engaged sheet form a said registered stack with a predetermined force, which feed means include feed legs positioned on each side of the pin means for engaging a said outside registered sheet at positions adjacent a said registration edge beyond each side of a said aperture, wherein the feed legs are spaced apart by a predetermined distance for causing deflection of a said holding strip for concentrating tension in a said separation region when a said holding strip of a said registered and engaged sheet is forced against the pin means by the feed means feeding a said registered and engaged sheet from a said stack, and for enabling the feeding of a said engaged sheet from a said stack.

15. A sheet registration and feeding combination according to claim 14, further characterized by the feature that the feed means include means for engaging the feed legs with a said registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning a said registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge.

16. A sheet registration and feeding combination according to claim 15, further characterized by the feature that the feed legs are variably disposed to the holding means in response to variations in the size of a said stack; and the feed means include spring means for providing a said applied force, which spring means are operatively responsive to a variation in the disposition of the feed legs in response to a reduction in the size of a said stack, for decreasing said provided applied force as the size of a said stack is reduced.

17. A sheet registration and feeding combination according to claim 15, wherein each said sheet is of a predetermined thickness; further characterized by the feature that each feed leg includes a step for applying a said force to compress a said stack and for engaging a said registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the surface of a said outside registered sheet adjacent a said registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging a said registration edge of a said outside registered sheet and for pushing against a said registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than a said thickness of each said sheet.

19. A sheet registration and feeding combination according to claim 18, further characterized by the feature that the thickness of the riser is slightly greater than the thickness of each said sheet.

21. A sheet registration and feeding combination according to claim 20, wherein each said sheet is of a predetermined thickness, further characterized by the feature that the feed means include means for engaging the feed legs with a said registration edge of a said outside registered sheet for enabling the feed legs to push against a said engaged registration edge to feed a said engaged sheet from a said stack; and the feed means include means for applying a force to compress a said stack for aligning a said registration edge of a said outside registered sheet with the feed legs to enable said engagement with a said registration edge; and each feed leg includes a step for applying a said force to compress a said stack and for engaging a said registration edge of a said outside registered sheet, wherein each step comprises a plate having a surface disposed for pressing against the exposed surface of a said outside registered sheet adjacent a said registration edge of a said outside registered sheet to apply a said force; and a riser joined to the pressing surface of the plate for engaging a said registration edge of a said outside registered sheet and for pushing against a said registration edge to feed a said engaged outside registered sheet from a said stack upon said feeding by the feed means, wherein the thickness of the step provided by the riser is not greater than a said thickness of each sheet; whereby a said provided force is applied by the plate to a said fed sheet during said feeding for preventing buckling near a said registration edge of a said fed sheet.

23. A sheet registration and feeding combination according to claim 13, wherein in each said sheet a said aperture is an isosceles triangle with the vertex adjacent a said separation region and the base parallel to a said registration edge, further characterized by the feature that the pin means has a semicircular holding surface for registration with a said sheet, wherein the pin means is disposed for registration of the flat surface of the pin means with a said base of a said aperture of a said sheet.

24. A sheet registration and feeding combination according to claim 14, wherein the dimensions defined by said registering portions of a said aperture edge is slightly larger than the corresponding dimensions of the pin means for preventing a snug registration, further characterized by the feature that the feed legs are disposed for dragging across a said outside registered sheet during an interval between the feeding of a fed sheet and the engagement of said outside registered sheet, which dragging provides a small opening between the pin means and a said holding strip of a said outside registered sheet.