US 3332317 A
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Description (OCR text may contain errors)
JURY 25, $2 E. PEQKMAN ET AL 3,332,3E7
CHALK SCREEN IMAGE PROJECTOR 5 Sheets-Sheet Filed May 19, 1965 FIG! INVENTORS: E C K M A N EUGENE F. P
ARTHUR W. CARLSON FRANK R. TORREY FI'G4 WITNESS AORNEYS JURY 25, 19%? PECKMAN ET AL 3,332,317
CHALK SCREEN IMAGE PROJECTOR 3 Sheets-Sheet 8 Filed May 19, 1965 INVENTORS,
ECKMAN A HUR W. CARLSON FRANK R. TORREY EUGENE F. P
WITNESS A ORNEYS July 25. 1967 E. F. PECKMAN ET AL 3,332,317
CHALK SCREEN IMAGE PROJECTOR 3 Sheets-Sheet 5 Filed May 1.9, 1965 III/l/l/l III/Ill III III! III I FIG. 8a
INVENTORS' EUGENE F PECKMAN ARTHUR W CARLSON FRANK RTORREY WITNESS ATTORNEYS 3,332,317 Patented July 25, I967 face 3,332,317 CHALK SCREEN IMAGE PRGJECTDR Eugene F. Peckman, Pittsburgh, Pa., Arthur W. Carlson,
Muskegon, Mich., and Frank R. Torrey, Silver Spring,
Md., assignors to E. H. Sheldon & Company, Muskegon, Miclr, a corporation of Michigan Filed May 19, 1965, Ser. No. 457,027 9 Claims. (Cl. 8824) ABSTRACT OF THE DISCLOSURE This apparatus relates to a chalk screen image projector, and more particularly to a screen having a writing surface in combination with means for projecting images through the scheen so as to become visible on the outer writing surface of the screen. The projector is housed within a cabinet and in which a door of the cabinet is equipped with the screen having the writing surface, and when the door is moved to an open position the projector is effective for directing an image through the screen of the door and the writing surface thereon to permit the use of the screen as a chalk board in connection with the projected image.
This invention relates to a chalk screen image projector, and more particularly to a screen having a writing surface in combination with means for projecting images through the screen so as to become visible on the outer writing surface of the screen.
An object of the invention is to provide a chalk screen projection center or apparatus in which a chalk board or writing surface is provided in the form of a screen and in combination with projection means for projecting images through the screen. A further object is to provide such a screen in a cabinet with the door of the cabinet providing the screen. A still further object is to provide in combination with the cabinet screen door, projection means housed within the cabinet when the door is closed but moved to operative position for projecting images through the screen of the door when the door is opened. A further object is to provide in such apparatus means for raising and lowering the projecting means to change the position of the projected image on the board or screen. A still further object is to provide a compact cabinet structure in which the projection mechanism is housed within the cabinet and in which a door of the cabinet is equipped with a screen having a writing surface, and when the door is moved to open position said projection apparatus is effective for directing an image through the screen of the door and the writing surface thereon to permit the use of the screen as a chalk board in connection with the projected image, thus avoiding shadows and glare during the use of the board and image. Other specific objects and advantages will appear as the specification proceeds.
The invention is shown, in illustrative embodiments, by the accompanying drawings, in which:
FIGURE 1 is a perspective view of a cabinet having a chalk board screen in accordance with our invention; FIG. 2, a perspective view of the structure shown in FIG. 1 with the door opened to position image-projecting apparatus for the projection of an image through the screen of the door; FIG. 3, a transverse sectional view, the section being taken as indicated at line 3-3 of FIG. 1; FIG. 4, a transverse sectional view, the section being taken as indicated at line 44 of FIG. 1; FIG. 5, a transverse sectional view, the section being taken as indicated at line 5 of FIG. 2; FIG. 1a, a view similar to FIG. 1 but showing a modified form of apparatus; FIG. 2a, a perspective view of the structure shown in FIG. 1a but with the door of the cabinet opened; FIG. 3a, a sectional view, the section being taken as indicated at line 3a-3a of FIG. 1a; FIG. 4a, a transverse sectional view, the section being taken as indicated at line 4a4a of FIG. 1a; FIG. 5a, a transverse sectional view, the section being taken as indicated at line 5a-5a of FIG. 2a; FIG. 6a, a detail sectional view, the section being taken as indi cated at line 6a-6a of FIG. 5a; FIG. 7a, a broken detail view, the view being taken as indicated at line 7a7a of FIG. 5a; FIG. 8a, a front view in elevation on an enlarged scale of the modified cabinet structure shown in FIGURE 1a but with the front door portions of the cabinet removed except for a portion at the top of the figure and the projector being removed; FIG. 9a, an end view in elevation of the cabinet shown in FIG. 8a with the end wall removed; and FIG. 10a, a top view of the cabinet structure shown in FIG. 8a with the top panel removed.
In the structure shown in FIGS. 1 to 5 inclusive, 10 designates a cabinet having side and rear walls and provided at its front with a door 11 supported on hinges 12. About midway of the door, there is provided a forwardly-extending chalk receptacle 13, and above the receptacle 13 is supported a screen 14 through which an image 15 shown in dotted lines in FIG. 2 is projected. The screen 14 has its outer surface treated or roughened to provide a chalk board surface so that the screen surface has a blackboard for the use of chalk, crayons, or other writing material.
The screen 14 may be formed of glass having a frosted front surface, or of glass provided on its outer surface with suitable plastic material which provides a transparent sheet but which also may be polished or treated to receive chalk impressions, etc. A plastic-coated glass panel not only is useful in transmitting the image therethrough so as to render it visible on the front surface thereof, but also the front surface readily receives and records chalk and other Writing materials.
The door 11 may be provided at its lower portion with small doors 16 and 17'to provide access to storage space in the lower portion of the cabinet for receiving transparencies, etc. In such space, an adjustable shelf 18 may be mounted as shown in FIG. 4.
Fixedly secured to the door 11 is a horizontal platform 19 whichswings outwardly and inwardly as the door is opened and closed. The platform 19 is connected to the cabinet by a chain 20 and the chain limits the outward swinging movement of the door 11.
A mirror or reflector 21 is carried by a backing or frame 22, and the frame is pivotally supported upon the platform 19 by the pivot rod 23. The reflector frame is anchored to the rear wall of the cabinet 10 by a chain 24. A tension spring 25 is anchored at one end to the platform 19 and at the other end to a lever 26 connected to the pivotally-mounted backing or frame 22. As the door is swung outwardly to operative position, as shown best in FIG. 5, the pivot rod 23 coacts with the chain 24 and the spring 25 to hold the reflector 21 in position for directing the image upon the screen 14.
An image projector 27 is supported upon table 28, and when a transparency is placed upon it, directs the image upwardly to a lens 29 carried by support arm 30. By means of the lens 29 and the reflector 21, the image is projected through the screen 14 and appears on the front face thereof, as indicated by the numeral 15 in FIG. 2.
Any means for supporting the table 28 may be provided. In the illustration given, we provide a standard 31 having feet 32 equipped with glider buttons 33, and upon the standard 31 is mounted a frame member 34 apertured to receive the rods 35. The rods 35 may be adjusted within the apertures and secured therein at the desired height by the use of set screws or other suitable means. Secured to the frame member 34 is a V-shaped support 36 having at their inner ends a slide member 37 mounted within the track 38 carried by platform 19, as shown best in FIG. 5. Thus, the inner end of the V- shaped support 36 is slidably carried within the track 38, and this support together with the pedestal 31 movably carries the table 28 upon which projector 27 is mounted.
Operation In the operation of the apparatus, the projecting mechanism 27 and associated parts are held within the cabinet, as shown best in FIGS. 1 and 3. In this position, the screen 14 is useful as a chalk board. When, however, the door is swung open until limited by the chain 2%) and the table 28 is drawn outwardly until the slide 37 reaches a stop at the end of the track 38, the apparatus is automatically in position for supplementing the chalk board 14 with a projected design. When the slected transparency is placed upon the projector 27 and the projector illuminated, the image therefrom is projected through the screen 14 so as to be visible on the :front face thereof. In the specific illustration given, a graph image is projected onto the screen, and the instructor or person using the chalk board may then draw the other lines insuperposed relation over the graph, as illustrated in FIG. 2. For example, problem constructions, graphs, coordinates, and other images may be projected upon the screen, and these may be copied or extended by the use of chalk, etc. as they appear on the screen. The screen thus becomes an actual work station, enabling the instructor or other person to utilize in the background the projected image while he makes modifications thereof. The user can stand next to the screen without casting shadows to interfere with his own view or the views of others.
When the projector is no longer to be used, the parts may be moved to closed position, as illustrated best in FIG. 3, the parts moving automatically into the position shown by merely moving the projection support structure inwardly and closing the door 11.
In the modification illustrated in FIGS. 1a to a inclusive, the cabinet 39 has an upper door 40 which extends over the upper portion of the cabinet only. The lower doors 41 and 42 extend over a fixed portion of the cabinet which may contain partitions 43 useful for re?- ceiving transparency plates, etc. Fixed to the upper door 40 is a chalk receptacle 44, and above it a screen 45 similar to screen 14 of FIGS. 1 to 5 inclusive.
Fixed to the door 40 is a platform 46 having drawer sides 47 and in which is mounted a slide 48. The rear end of the slide 48 is preferably provided with partitions 49 adapted to receive transparencies, etc.
A reflector 50 is carried by frame member 51. A chain 52 connects one end portion of the frame to the rear side of the cabinet 39. A spring 53 connects the other end of the frame 51 to a side wall of the cabinet 39. The frame 51 is pivotally mounted upon platform 46 in the manner shown best in FIGS. 9a and 10a. A pivot strap 54 has a lower apertured end receiving a pivot pin 55 and a similar apertured upper end receiving a pivot pin 56. The pivot pin 56 connects the apertured upper end of strap 54 to a pair of straps 57 and 58 which have their forward ends connected to the door 40.
The cabinet 39 has an intermediate fixed transverse partition wall 59 extending across the cabinet just below the platform 46, as shown best in FIG. 9a, and this partition is provided with a stop member in the form of a screw 60 which engages a flange stop 61 carried by the platform 46, as shown best in FIG. 6a, so that, when the platform 46 has been swung outwardly to the operative position shown in FIG. 5a, the stops 60 and 61 limit further outward movement of the platform.
A projector 27a, similar to projector 27 hereinbefore described, is carried by a table 62, and the transparency image is directed by lens 63 upon the reflector 50. In
order to fold the table 62 compactly within the cabinet 39, we mount the table eccentrically upon the slide member 48 and also provide mechanism for raising and lowering the table 62. As shown best in FIG. 9a, the table 5 62 is eccentrically mounted at 64 upon plate 65, and plate 65 is connected by lazy tong links 65a to a lower plate 66. By means of a screw engaging a nut connected with the plate 66 and operated by handle 67, the link members are caused to raise and lower to elevate the table 62. Since such lifting structure is well known, a further detailed description herein is believed unnecessary.
In order to limit the rotation of the table 62 upon the plate 65 therebelow, we provide these members with angle stops 68, as shown best in FIG. 7a.
In the operation of the modified structure shown in FIGS. la to 10a inclusive, the door 40 which covers the upper portion of the cabinet is moved inwardly and outwardly. When moved outwardly to the operative position shown in FIG. 5a, the slide 48 is drawn outwardly, and the table 62 is swung on the eccentric pivot 64 to the position shown in FIG. So so that the image is directed from the lens 63 upon the reflector 50 and therefrom through the screen 45. In this operation, the reflector is drawn automatically to the proper position shown in FIG. 5a.
When the parts are to be moved back into the cabinet, the table 62 is rotated to the position shown in FIG. 3a and the slide 48 is moved inwardly, and then the door 49 is moved to closed position. The reflector structure is brought automatically to the position alongside the rear wall of the cabinet, as shown in FIG. 3a.
While in the foregoing specification we have shown specfic structures in considerable detail for the purpose of illustrating embodiments of our invention, it will be understood that such details may be varied widely by those skilled in the art without departing from the spirit of our invention.
1. In combination with a cabinet provided with a door, said door having as a panel thereof a translucent screen with a front chalk-receiving surface, image projector means, reflector means associated therewith for projecting an image through said screen from the rear thereof and D visible from the front thereof, and cooperating means on said door and cabinet for aligning said projector and refiector means in operative position when the door is opened to a predetermined position.
2. The structure of claim 1 in which means are provided for raising and lowering the projector for changing the position of the image on said screen.
3. The structure of claim 1 in which means are provided for moving said projector and reflector means into folded position within said cabinet.
4. In combination with a cabinet having a chamber in the upper portion thereof, a door closing said chamber, said door having as a panel thereof a translucent screen with a front chalk-receiving surface, image projector and reflector means associated with said door for projecting an image through said screen from the rear thereof and visible from the front thereof, means for folding said projector and reflector means compactly within said cabinet when the door is closed, and means for swinging said projector and reflector means outwardly when said door is opened.
5. In combination, a cabinet equipped at its front with a door having a translucent screen provided with a chalkreceiving front surface, a platform fixed to said door, a reflector carried by said platform, means associated with 70 said platform for supporting a projector member outwardly fro-m said door when said door is opened, and means for aligning said reflector and projector means for directing an image through said screen when said door is opened to operative position.
6. The structure of claim 5 in which said supporting 5 means for said projector is equipped with a pedestal and feet adapted to rest upon the floor.
7. The structure of claim 6 in which said supporting means is carried by said platform.
8. In combination with a cabinet provided with a door having a panel thereof a translucent screen with a front chalk-receiving surface, image projector means and reflector means associated therewith for projecting an image through said screen from the rear thereof, a platform carried by said door extending inwardly of said cabinet, a slide member carried by said platform, a table for sup porting said projector means eccentrically mounted upon said slide member, and cooperating means on said door and cabinet for aligning said projector and reflector means in image-projecting position when said door is opened to a predetermined position.
9. The structure of claim 8 in which said slide member is provided with means for raising and lowering said table.
References Cited UNITED STATES PATENTS 1,242,674 1 0/1917 Fleischer 352--51 1,589,349 6/ 1926 Bavsch et a1. 8824 1,787,309 12/1930 Gol-dbeck 352- 243 1,840,920 1/1932 Spaulding 88-24 2,474,297 6/ 1949 Young 88 24 2,522,351 9/1950 Egolf 3566 3,051,040 8/1962 Davis 8824 FOREIGN PATENTS 572,528 10/ 1945 Great Britain.
NORTON ANSHER, Primary Examiner. R. M. SHEER, Assistant Examiner.