US3860230A

US3860230A - Sheet transport and flattening apparatus

Info

Publication number: US3860230A
Application number: US316760A
Authority: US
Inventors: Michael P Georges
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-06-18
Filing date: 1972-12-20
Publication date: 1975-01-14
Anticipated expiration: 1992-01-14

Abstract

A flexible sheet transport has a flat bed support slidable past a guide bar having a set of vertical guide holes in which a set of rods slide and are downwardly urged to hold a sheet in contact with the moving flat bed support. The flat bed has cam surfaces for lifting the rods out of contact with the sheet to facilitate insertion and removal.

Description

United States Patent [191 Georges [4 Jan. 14, 1975 1 SHEET TRANSPORT AND FLATTENING APPARATUS [76] Inventor: Michael P. Georges, PO. Box 800,

Walpole, Mass. 02062 22 Filed: Dec. 20, 1972 21 Appl. No.: 316,760

Related U.S. Application Data [62] Division of Ser. No. 47,264, June 18, 1970, Pat. No.

[52] U.S. Cl. 271/3, 271/267 [51] Int. Cl B65h 5/04 [58] Field of Search 271/54, 55, 3, 8, 63, 48, 271/50, 58, 60, 84,45; 35/48 B; 355/72, 75, 76; 248/361 [56] References Cited UNITED STATES PATENTS 1,209,912 12/1916 Waite ..271/58 1,530,275 3/1925 Meamone 271/50 2,196,240 4/1940 Whitehead... 271/54 2,495,887 1/1950 Bumstead 355/76 3,412,484 11/1968 Evans et a1 35/48 B Primary ExaminerEvon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr.

Attorney, Agent, or FirmDike, Bronstein, Roberts, Cushman & Pfund [57] ABSTRACT A flexible sheet transport has a flat bed support slidable past a guide bar having a set of vertical guide holes in which a set of rods slide and are downwardly urged to hold a sheet in contact with the moving flat bed support. The flat bed has cam surfaces for lifting the rods out of contact with the sheet to facilitate insertion and removal 5 Claims, 6 Drawing Figures PATENTEU JAN I 4l975 SHEET 20F 2 I q I k SHEET TRANSPORT AND FLATTENING APPARATUS RELATED APPLICATION This application is a division of my copending application Ser. No. 47,264, filed June 18, 1970,.now US. Pat. No. 3,722,111.

BACKGROUND OF THE INVENTION This invention relates to electronic examination paper test scoring devices of the type wherein the examination is multiple-choice type and the test score is obtained by comparing the pattern of multiple-choice answers selected and placed by the student onto a test answer sheet with the correct answer pattern contained in a master answer device. Devices for grading papers based on this general arrangement are well known and range from the large automatic machines for grading large numbers of examination papers at high speed, such as the device described in US. Pat. No. 3,050,248, to various smaller machines adapted for use in the individual classroom wherein the examination papers are manually fed through the grading station.

The present invention relates to the smaller type machine that preferably uses conventional 8 /2 X 11 inch size test answer sheets and is adapted for use in the individual classroom or in a central office of a smaller school with the operation being convenient mechanically and yet rapid and reliable so as to permit the individual teachers to grade the papers for a days examination of all his students in a very brief period of time, while at the same time providing economy and reliability which is necessary to encourage the widespread adoption of such a device in smaller school entities.

In the preferred form the examination paper and the scoring sensors are laid out in strictly rectilinear fashion so that there is no unusual configuration of the sheet as far as offsetting columns of answers or of the detectors for the various columns thereby eliminating the necessity for an abnormal marking pattern as is the case where staggered rows of answer columns are used. Further, the preferred form uses a set of photo detector devices having a latching characteristic and is employed so that plural columns of questions containing multiple answers in each row are detected simultaneously as the row passes beneath the sensor row and by means of an electronic scan the incorrect and omitted answers are read from the scanned row during the interval when the next row of answers is moving to the sensor position. The speed of operation of the device is such that a simple in and out movement of the answer sheet past the sensor row accomplishes a complete page scan and answer totalizing thereby giving the teacher the results of an individual paper with extreme speed and simplicity of operation.

The object of the invention therefore is to provide a paper transport such as may be used in a high density examination paper using small response marks and that is easy and convenient for the student to use, which is graded in a grading machine which accommodates the same thereby providing a multiple-choice examination paper grading system which permits more examination questions to be answered in a conventional size, for example, 8% X 11 inch test paper than has heretofore been possible in a small low cost system. The optics of the apertures in the system are so arranged that extremely high accuracy of grading is obtained with a considerable tolerance latitude permitted in the physical alignment of the parts. Thus the unit is well adapted for use by the everyday teacher at the end of the class period who can operate the device with confidence although they do not possess any particular skill in aligning and feeding the examination papers through the device.

IN THE DRAWINGS FIG. 1 is a perspective view of one preferred arrangement of the paper grading machine with an examination paper and a permanent master answer-aperture plate shown in place for operation.

FIG. 2 is a view along the same lines as FIG. 1, with cover removed to show various internal features of the device.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention comprises a housing 11 having a front panel 12, upon which a numerical indicator 13 is supported. The indicator 13 provides a readout of the test score and may conveniently consist of a window through which numerals of a pair of electronic indicator tubes appear. Also mounted on the panel are on-off switch 14 and pilot light 15.

The front panel contains a sliding support bed or carriage 16 which is mounted on a conventional drawer extension slide assembly 17 so as to permit the'support bed 16 to be fully extended as shown to receive an examination paper or test answer sheet 18 thereon. The examination paper is positioned by a series of pins 19 and a paper stop in the form of an elongated slotted bar 21. The examination paper 18 rests upon and is supported by a rigid master answer-aperture plate 22. The answer-aperture plate 22 is mounted on the support bed frame 16 and aligned properly within the positioning boundaries l9 and 21 on the support bed frame 16 and is opaque except for the apertures 49 and 47. Alternatively, a transparent support plate could be used covered by an opaque surface with the appropriate aperture pattern. Thus with the answer-aperture plate 22 aligned with and the examination paper 18 in place be: tween the positioning posts 19 and the edge of the paper positioning bar 21 assures that the aperture plate 22 and examination paper 18 are in appropriate registry in relation to the design centers and as will hereinafter appear provides sufficiently accurate registration to assure uniform light detection properties during the sensing operation.

The support bed 16 is capable of being slid into the housing 11 on the extension slide assembly 17 by holding the handle 23 and the procedure for grading a paper is to place the examination paper 18 on answeraperture plate 22 as shown in FIG. 1, pushing the support bed or carriage l6 completely into the housing 11, and withdrawing it again to the position shown in FIG. 1. In doing this operation the examination paper is graded and the correct test score appears at the indicator window 13. During the scanning of the examination paper in order to maintain optical uniformity and to prevent light leakage around the examination paper apertures the examination paper 18 must be kept flat and in reasonable contact with the aperture plate 22 in the vicinity of the photo sensing area. As the sliding motion of the support bed 16 takes place a series of light weight Teflon rods 24 which are loosely supported in vertical holes in a bar 20 act as weights to hold the examination paper 18 flat against the top surface of the answer-aperture plate 22 at the photo sensing area without unduly weighting the paper or having any tendency to bind, buckle or otherwise distort the thin light transmissive sheet on which the examination paper 18 is printed.

Referring now to FIG. 2, the interior construction details are shown which include a second bar 25 having a series of vertical holes therein in which are loosely mounted a second series of light Teflon rods 26 fitted to act as a paper flattener in sliding contact with the surface of the examination paper 18. On the front surface of the bar 25 are mounted a plurality of lamps 27 which project a beam downwardly, the axis of which is aligned with the reception aperture of

photo detector devices

28 and 48. The actual light transmission between the lamps 27 and the

photodetector devices

28 and 48 is through a rectangular aperture 29 in a bar 31 which covers the

photo detectors

28 and 48 throughout its length. This rectangular aperture cooperates with the predetermined shape of the apertures in examination paper 18 and aperture plate 22 to eliminate excessive light leakage between adjacent apertures in both the horizontal and vertical directions. To aid in eliminating this misdirected light leakage the top surface of the bar 31 which covers the

photodetectors

28 and 48 and contains apertures 29 is placed as close as reasonable manufacturing tolerances permit to the bottom surface of the aperture plate 22. This technique masks off given areas and thereby cuts down on the light acceptance area and the light acceptance angle to the

photodetector devices

28 and 48. In the view shown in FIG. 2 the bar 31 is broken away at the left hand end to disclose the general position of the photodetector devices 28. It will be noted in FIG. 2 that the paper flattening rods 26 are aligned in a row parallel and to the rear of the row of lamps 27 and by referring back to FIG. 1 it will be recognized that the row of paper flattening rods 24 is aligned on the front of the row of lamps 27. Thus the aligned lamps 27 and photo detectors 28 constitute a sensor row which is flanked on both sides by the rows of paper flattening'rods 24 and 26 thereby holding the examination paper in close contact with the aperture plate 22 at the photosensing area during the transit of the aligned examination paper and answer-aperture plate between the row of lamps 27 and the row of rectangular apertures 29.

The paper stop bar 21 is provided with a downwardly sloping edge 32 which acts to quickly lead into position and to keep the forward edge of the examinaton paper down in contact with the answer-aperture plate 22 along the paper stop bar edge. Other configurations for holding down the foreward edge of the examination paper may be used such as clips or, as illustrated in FIG. 1, a long horizontal slot 34 in the paper stop bar 21. The bar 21 is also provided with a plurality of sloping slots 30 which are positioned in alignment with the

rods

24 and 26. The lower ends of the

rods

24 and 26 have rounded ends thereby providing a cam action when engaged with the bottom surface of the slots 30 to lift the rods out of the way as the paper stop bar 21 slides underneath the bars 20 and 25 in which the rods are slidably mounted. When the support bed 16 is fully extended outside the housing 1 1 the

rods

24 and 26 rest on the paper stop bar 21 out of the way of an examination paper 18 that is to be inserted for scoring and later removed. In order to record a score the examination paper 18 is inserted onto the support bed 16, the support bed 16 and examination paper 18 are pushed into the housing 1 l to the closed and fully retracted position and then pulled out of the housing 11 into the fully extended position. As the examination paper 18 is pushed inward the

rods

24 and 26 come down onto the paper to accomplish their flattening action and later retract out of the way as the examination paper is pulled out of the housing 11 for removal. As the examination paper 18 goes inward its leading edge is held down by the downwardly sloping edge 32 or by other means for accomplishing the same task so that the lower rounded ends of

rods

24 and 26 can enter over the examination paper leading edge without hitting it. Other means of lowering the

rods

24 and 26 onto the examination paper 18 without hitting against the examination paper leading edge and later lifting these

same rods

24 and 26 off the examination paper 18 and out of the way may be used. Except for controlled exposing to light through apertures, the

photo detector devices

28 and 48 must be kept covered from the lamps 27. The paper stop bar 21 acts in a light shielding function as an extension of the aperture plate 22 and keeps light emitting from the lamps 27 from projecting onto the

photo detector devices

28 and 48 when the support bed 16 is fully extended out of the housing 11. At the end of the inward travel of the slides 17 the support bed 16 contacts a microswitch actuator 33 which provides a clear or reset signal to the electronic visual display devices which appear at the window 13. Thus the operation of the photo detector devices 28 during the inward travel of the support bed 16 is cleared and the examination paper is graded during the withdrawal of the support bed 16 thereby giving the final answer readout when the examination paper is once again in the position shown in FIG. 1 and ready to be removed from the answer-aperture plate 22 by the teacher.

The extremely simple arrangement for examination grading shown provides high reliability and accuracy with the line by line photo sensing of a plurality of answers in the columns of the examination paper where each light transmission aperture is permitted to sense the necessary light signal from the lamps 27 as the row of combined photodetector apertures 46 and 49 passes the sensor row.

Although test answer sheet scanning by manually moving the slide has been disclosed this motion can be motorized or other modifications can be made by those skilled in the art without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A flexible sheet transport and sheet flattening device comprising:

a. a flat bed support for a thin flexible sheet;

b. means for translating said flat bed support to move substantially horizontally past a transverse line;

c. a guide bar positioned above and generally parallel to said transverse line and having a set of substantially vertical guide holes therein;

(1. a set of rods slidably supported and downwardly urged in said set of guide holes and supported on said flat bed support as it moves past said transverse line to maintain said flexible sheet in substantial contact with said support in the vicinity of said transverse line and e. means carried by said flat bed support for contacting and automatically lifting said rods from contact with said flat bed support at a predetermined position thereof to facilitate insertion and removal of said sheets without contacting said rods.

2. A device according to claim 1 in which said means for automatically lifting said rods from contact with said flat bed support comprises: an end stop in the form of a transverse plate at one end of said support to provide an edge against which the edge of said flexible sheet can abutt, said edge containing a set of slots with inclined plane bottom surfaces and being aligned with said set of rods to lift said rods when said support is moved to position said plate at said transverse line, said rods having rounded ends to provide a smooth transition surface as the said rods enter onto the said end stop inclined slots.

3. A device according to claim 2 and including a second guide bar and set of rods slidable therein located on the opposite side of said transverse line to bear on said flexible sheet on both sides of said transverse line.

4. Apparatus according to claim 2 in which said edge of said plate is inclined to provide a downwardly sloping surface for guiding the forward edge of a sheet placed on said support.

5. Apparatus according to claim 4 in which said downwardly sloping surface terminates in a horizontal slot for retaining said forward edge of said sheet.

Claims

1. A flexible sheet transport and sheet flattening device comprising: a. a flat bed support for a thin flexible sheet; b. means for translating said flat bed support to move substantially horizontally past a transverse line; c. a guide bar positioned above and generally parallel to said transverse line and having a set of substantially vertical guide holes therein; d. a set of rods slidably supported and downwardly urged in said set of guide holes and supported on said flat bed support as it moves past said transverse line to maintain said flexible sheet in substantial contact with said support in the vicinity of said transverse line and e. means carried by said flat bed support for contacting and automatically lifting said rods from contact with said flat bed support at a predetermined position thereof to facilitate insertion and removal of said sheets without contacting said rods.