US3640601A

US3640601A - Projection screens

Info

Publication number: US3640601A
Application number: US886056A
Authority: US
Inventors: Louis Daniel Murray
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-18
Filing date: 1969-12-18
Publication date: 1972-02-08
Anticipated expiration: 1989-02-08

Abstract

In the present device the screen is rotatably mounted along the lower ends of its sides by brads to vertical support arms, while the upper portion of the screen is fastened to a cord which is retained in an adjustable keeper so adjustment of the tilted position of the screen is provided by loosening or tightening of the cord. Vertical adjustment of the screen is provided by spaced pairs of slots in the vertical support arms, these slots accommodating the supporting wall hooks.

Description

United States Patent Murray 1 Feb. 8, 1972 [54] PROJECTION SCREENS [72] Inventor: Louis Daniel Murray, 5216 Ponderosa Way, Dallas, Tex. 75227 [22] Filed: Dec. 18, 1969 [2]] App]. No.: 886,056

[52] US. '0/117 [51] Int. Cl. G03b 21/56 [58] field Search ..350/1 17 T; 352/36; 248/454,

[56] References Cited UNITED STATES PATENTS 1,422,149 7/1922 Troeger ..3so/123 3,255,988 6/1966 Albee,.lr ..350/|17x Primary Examiner-Louis R. Prince Assistant ExaminerJoseph W. Roskos [57] ABSTRACT In the present device the screen is rotatably mounted along the lower ends of its sides by brads to vertical support arms, while the upper portion of the screen is fastened to a cord which is retained in an adjustable keeper so adjustment of the tilted position of the screen is provided by loosening or tightening of the cord. Vertical adjustment of the screen is provided by spaced pairs of slots in the vertical support arms, these slots accommodating the supporting wall hooks.

10Claims, IZDravvingfigures PATENTED EB 8 I972 SHEET 1 OF 2 INVENTOR LOUIS DANIEL MURRAY PATENTEDFEB 81972 3.640.601

INVENTOR LOUIS DANIEL MURRAY PROJECTION SCREENS This invention relates to projection screens of the adjustable type, and particularly to projection screens mounted from a pair of wall supports such as provided on a classroom map rail.

The primary object of my invention is to provide a projection screen of the type stated which may be easily adjusted in height, in tilt angle, and in lateral position thereby providing a wider range of viewing positions than provided by known devices.

A further object of my invention is to provide a projection screen as described above which is attractive, simple to install and adjust, and which may be easily moved to another location, say from the front of the room to the back, or to another room.

A still further object is to provide a projection screen of the type stated which is of simple construction and yet is durable, and which is economical to manufacture.

Other objects and advantages will become apparent from the detailed description hereinafter appearing.

In the accompanying drawings illustrating the invention in the several figures of which like parts are similarly designated.

FIG. 1 is a perspective view, from the back side, of a projection screen embodying my invention, and is shown in a forwardly tilted viewing position. FIG. 2 is a perspective view, also from the back side, of the screen shown in FIG. 1, now shown in the vertical untilted position.

FIG. 3 is a front elevation view of the cord-retainer clip.

FIG. 4 is a sectional perspective view taken along a vertical plane approximately parallel with the screen and through the cord-retaining aperture of the lower frame part, wherein the cord-retainer clip is shown in the released position.

FIG. 5 is a sectional perspective view of the elements shown in FIG. 4, except the cord-retainer clip is here shown in the engaged, or locking position.

FIG. 6 is a transverse sectional view of the lower right hand comer of the screen, showing the frame part and the vertical support arm, and the assembly elements connecting these parts taken approximately along the lines 6-6 in FIG. 2.

FIG. 7 is a sectional perspective view of a slightly modified version of the device shown in FIGS. 1-6, wherein one of the two alternate cord-retaining devices are shown.

FIG. 8 is a sectional perspective view of a slightly modified version of the device shown in FIG. 7.

FIG. 9 is a vertical elevation view of the tilt-adjusting elements of the device of FIG. 8.

FIG. 10 is a perspective view, form the front, of a slightly modified screen frame embodying some of the basic features of my invention, and

FIG. 11 is an elevation view of the back side of the mounting frame of the device of FIG. 10.

FIG. 12 is a side elevation view of the modified screen of FIG. 10.

Referring now to the drawings by characters of reference, the projection screen 10 as shown in FIGS. 1 and 2 has a rigid foam viewing screen 11, to each surface of which is bonded an aluminum foil layer 12, the front surface of which is provided with a light coat of white vinyl 13, thereby providing a highly light sensitive surface for increasing image clarity.

Four extruded frame sections 14 are provided with their ends mitered and fitted together, these comprising a snug fitting frame for the screen, to which they are bonded with a suitable adhesive.

Front and

back lips

14a, 14b are provided normal to the inner face of each of the frame sections 14, these lips together with the inner section face forming a cavity for the screen 11. The faces of each frame section 14 further extend toward the back beyond the back lip 14b comprising a lip 140, as seen in FIG. 6.

Two upright tubular support arms 15 are provided, and are connected to the two vertical frame sections 14' with brad pins 17 rotatably fastened through the lower ends of the sections 14', spacing washers 18, the frame section lips 14c and locking friction nuts 19, as best seen in FIG. 6.

The effect of the mounting brad pins 17 being so located is to allow the weight of the screen 11 to cause its rotation, unless restrained, about the pin 17, tilting its top forward as shown in FIG. 1.

The upright arms 15 are further provided on their back sides with vertically matched pairs of spaced vertical slots 21, these slots 21 being adapted to accommodate hooks 22 of a map rail 29 so that use of the highest pair of the slots 21 gives the lowest possible position of the projection screen 10, and use of each successive pair of the slots 21 gives a higher position.

An adjustable threaded rod 23 is screwed through the bottom end of each arm 15 below the fastening brad pin 17 and normal the wall on which the device is used. The rod 23 is provided of sufficient length for approximately three-fourths inch to extend on either side of the arm 15, and each rod 23 is provided with a rubber front grip 24, comprising a finger grip for adjustment and a back grip 24 comprising a protective cushion against the blackboard or other surface against which the device is mounted.

A mounting cord 25 has its ends 25a secured respectively through the upper ends of the arms 15. Two grommets 26 are fastened through a pair of facing holes in the upper sections of the lips of the sections 14, and the cord 25 is slidably disposed through these grommets 26, and is provided of such length that when extended tautly by the weight of the screen 11 the device is in its maximum tilt position, as shown in FIG. 1.

An adjusting cord 27 is also provided and is attached at its upper end to the middle of cord 25. In the present embodiment this is accomplished by passing one of the ends of the cord 25 through a hole pierced in the upper end of cord 27, which is made of nylon, and whose tip is heat-fused to prevent ravelling, although the same effect could be achieved by means of a knot about the cord 25.

A hole 28 is provided in the middle of the bottom frame section 14A through the lip 14c, in which the adjusting cord 27 is slidably disposed. A flexible cord-retainer 30, preferably formed of polyethylene plastic, is provided, with a conical tip 30a formed normal to and at one end of a horizontal arm section 30b, whose other is fastened to the lip 140 by a brad 30d or the like so the tip 30a is disposed within the hole 28 also. A finger grip 30a is provided on the bottom of the arm section 30b, below the tip 300, and a series of ridges 30f are provided on the front face of tip 30a, all as best seen in FIGS. 1-5.

When the cord-retainer 30 is in the fully engaged position the ridges 30f press into the cord 27 and thus retain it in position in the hole 30, as seen in FIGS, 1, 2 and 5.

To adjust the tile position of the screen 11, the operator grasps the finger grip 302 and holds this down, thereby causing release of the cord 27 by the cord-retainer 30, as shown in FIG. 4, thereby permitting either increasing or decreasing the screen tilt angle by the operators pulling down on the lower cord end 27a or by his permitting the cord 27 to be pulled upward through the hole 28 by the weight of the tilting screen 11. When the desired angle has been reached the tip 30a is again placed in the fully engaged position wedged against the cord 27 holding it in place. I may also provide a cordretainer clip without the ridges 30f, as a plain conical-shaped tip may suffice. I

One of the important advantages of this invention lies in the fact that the tilt angle may be adjusted completely by operating below the level of the viewing screen 11, thereby permitting such adjustment even when the screen 10 is mounted above the operators head.

I may also provide a slightly modified version of my invention, wherein the single cord 25 is replaced by a pair of cords 25', the ends of each of which are fastened respectively to the upper ends of the frame sections 14 and the arms 15, as shown in FIG. 7. In this version, the single cord 27 is replaced by two adjustment cords 27', each of which joins at its upper end to the middle of the corresponding cord 25' as in the previous embodiment, while the lower end of each passes through a clip 31, which is provided with a tightening screw 32 for locking the cord 27' in place, all as seen in FIG. 7.

I may provide a second slightly modified form of my invention by providing the alternate adjustment cord arrangement as shown in FIG. 8, wherein each cord 27' is replaced by a modified cord 27" and each of the cords 25 is replaced by two flat strips 33, one rotatably mounted on the frame section 14', the other on the support arm 15, and both rotatably joined together at their other ends along with the upper end of the cord 27", by means of a brad 34, all as best seen in FIGS. 8 and 9. l have found that the cord 27" may be flattened at one end by pressing the end of a piece of nylon cord between two hot flat surfaces. This end flattens and rigidities, thus permitting perforation of this flattened end to admit the brad 34.

I may provide a yet further modified embodiment 40 of my invention as shown in FIGS. 10, 11 and 12, wherein the viewing screen 1 1 has been omitted, as this will be replaced in this embodiment by a rollup-type screen, such as a vinyl window shade. The supporting frame 40A of the modified device comprises a horizontal section 41 fastened at its ends to the lower ends of a pair of converging T-sections 42 by two brads 43, with the T-sections 42 fastened at their upper ends to a vertical screen support arm 44. The lower end of this arm 44 is secured between the upper ends of the T-sections 42 by a screw 50 or the like, and is further provided at its lower end with a horizontal stabilizing rod 45 which is fastened at its ends to the T-sections 42. A hook 46 is provided at the upper end of arm 44 for engaging the pull of a rollup-type screen. Holes 41a are provided in the ends of Section 41 by which brackets suitable for mounting a rollup screen may be attached. The converging support arms are provided fastened together at their upper ends by a short cross member 47 and are rotatably attached to the ends of the T-sections 42 at their lower ends by brads 48 or the like. An adjustment cord 49 is attached at its upper end to the cross member 45, passes over and is slidably retained by the cross member 47 and is slidably disposed in the clip 31 which is attached to the middle of the horizontal member 41, all as best seen in FIGS. 10 and 12. The tile angle of the frame 40 is accomplished by lbwering or raising the cord 49 after loosening the clip screw 32. As in the other embodiments the weight of screen and frame cause the device to tilt forward upon release of the adjusting cord 49.

Having thus described my invention what I claim and desire to secure by letters patent is:

I. In a projection screen, an adjustable screen comprising a frame, a pair of support arms, said frame being rotatably mounted to the lower ends of said arms by brads or the like, said mounting brads being located in a plane between the center of gravity of said frame and the plane of the wall on which the device is mounted, a restraining cord attached at its upper end to the top of said frame, its lower end being retained by an adjustable clip provided on the bottom section of said frame, said arms being provided with matched pairs of slots along their back faces for engaging the hooks of of an ordinary classroom map-rail, or like supports.

2. The device of claim 1 wherein said arms were vertical and parallel, and wherein a viewing screen is disposed within said frame beyond which said frame extends rearwardly comprising a lip, the lower ends of said arms being rotatably mounted on said lip.

3. The device of claim 2 wherein two facing holes are provided in the rearwardly extending lips of the upper ends of the sides of said frame, an upper cord or wire is provided and is slidably disposed within said facing holes, the ends of said upper cord being attached to the upper ends of said support arms with the upper end of first said restraining cord attached to the center of said upper cord so that lowering or releasing the lower end of said cord respectively decreases or increases the tilt of said viewing screen.

4. The device of claim 3 wherein a hole is provided in the lip of the bottom of said frame section, and the lower end of said cord is slidably disposed with said hole, and wherein a removable conical wedge member is provided and is disposed within said hole alongside said restraining cord with its larger portion beneath said hole, said wedge member comprising an adjustable clip.

5. The device of claim 4 wherein said wedge member is provided with a resilient horizontal arm, the end of which is fastened to the bottom surface of said bottom frame member, said arm comprising a spring for maintaining said wedge member in position in said hole, and wherein said wedge member is further provided with a lower projection comprising a finger grip for facilitating disengagement of said wedge member from the said hole.

6. The device of claim 1 wherein each lower end of said arms is provided with an adjustable threaded rod normal to its back face with approximately three-fourths inch extending both front and back, each end being provided with a flexible cushioning tip.

7. The device of claim 6 wherein a pair of upper cords is provided, each joining at one of its ends to the upper end of one of the respective vertical sides of said frame and each joined at its other end to the upper end of the corresponding said support arm, wherein two adjustable clips are provided, one on the lower end of each said arm, and two lower cords are provided, joined at their upper ends respectively to the middles of said upper cords, and their lower ends being slidably disposed within said adjustable clips respectively.

8. The device of claim 6 wherein a pair of adjusting cords are provided, and wherein two pairs of flat strips are provided, such that one strip of each pair is rotatably mounted at one of its ends on the upper end of said arm and in each pair the remaining ends are rotatably joined together along with the upper end of one of the said cords; and wherein two adjustable clips are provided, one on the lower end of each said arm, with the lower ends of said cords being slidably disposed within said clips respectively.

9. The device of claim I, wherein a horizontal T-section, two frame arms, and a central support are are provided, with the lower ends of said frame arms fastened to the ends of said horizontal T-section, the lower end of said central support arm is fastened between the upper ends of said frame arms, the upper end of said central support arm is provided with a hook for engaging the top of a rollup screen, the said T-section, frame arms, and screen support arm comprising a screen frame, and wherein the first two support arms are rotatably mounted at their lower ends to the lower ends respectively of the two said frame arms, and joined together at their upper ends by a short horizontal rod; and wherein the ends of said horizontal T-section are provided with holes for the mounting of the ends of a rollup screen, as set forth.

10. The device of claim 9 wherein the lower ends of the first said support arms are each provided with an adjustable threaded rod normal to the plane of these arms, and extending approximately three-fourths inch on each side, wherein each end of said rod is provided with a flexible tip.

Claims

1. In a projection screen, an adjustable screen comprising a frame, a paiR of support arms, said frame being rotatably mounted to the lower ends of said arms by brads or the like, said mounting brads being located in a plane between the center of gravity of said frame and the plane of the wall on which the device is mounted, a restraining cord attached at its upper end to the top of said frame, its lower end being retained by an adjustable clip provided on the bottom section of said frame, said arms being provided with matched pairs of slots along their back faces for engaging the hooks of of an ordinary classroom map-rail, or like supports.

8. The device of claim 6 wherein a pair of adjusting cords are provided, and wherein two pairs of flat strips are provided, such that one strip of each pair is rotatably mounted at one of its ends on the upper end of one said arm and in each pair the remaining ends are rotatably joined together along with the upper end of one of the said cords; and wherein two adjustable clips are provided, one on the lower end of each said arm, with the lower ends of said cords being slidably disposed within said clips respectively.

9. The device of claim 1, wherein a horizontal T-section, two frame arms, and a central support are are provided, with the lower ends of said frame arms fastened to the ends of said horizontal T-section, the lower end of said central support arm is fastened between the upper ends of said frame arms, the upper end of said central support arm is provided with a hook for engaging the top of a rollup screen, the said T-section, frame arms, and screen support arm comprising a screen frame, and wherein the first two support arms are Rotatably mounted at their lower ends to the lower ends respectively of the two said frame arms, and joined together at their upper ends by a short horizontal rod; and wherein the ends of said horizontal T-section are provided with holes for the mounting of the ends of a rollup screen, as set forth.