US3315930A - Portable projection screen stand - Google Patents

Description

April 25, 1967 G. COTA 3,315,930

PORTABLE PROJECTION SCREEN STAND Filed May 24, 1965 30 INVENTOIQ m gt-MN L. COTA [48 HF BY W 9 dfttgjs.

were relatively United States Patent Ofilice 3,315,930 PORTABLE PROJECTION SCREEN STAND Glenn L. Cota, Waukegan, Ill., assignor to Radiant Manufacturing Corporation, a corporation of Illinois Filed May 24, 1965, Ser. No. 458,316 4 Claims. (Cl. 248171) This invention relates to a portable projection screen assembly and, more particularly, to a stand construction for such screen assembly that is movable between ex tended column-supporting position and retracted storage position. Further, this invention relates to an improved stand construction for a portable projection screen having legs that are manually extensible to column-supporting position, such legs being automatically retracted when the stand construction is lifted from a supporting surface,

Heretofore, it has been proposed that the supporting legs of a portable stand construction be pivotally carried at one end on the bottom of a standard and that spring structure and cooperating linkage be provided within the standard for automatically retracting the legs upon lifting of the portable projection screen assembly from a supporting surface. Sometimes, the spring for retracting the legs was cocked responsive to movement of a telescoping rod which was extended from the standard for supporting the projection screen in use position. Such arrangements complex and, therefore, expensive. Further, the springs and cooperating linkage were sometimes subject to malfunctions.

There is disclosed in the copending application, Ser. No. 444,328, filed Mar. 31, 1965, of Glenn L. Cota and Albert T. Worden and entitled Stand Construction For Portable Projection Screen, an improved form of stand construction that is less complex and, therefore, less expensive than the prior construction noted above. The present invention represents a further improvement.

An object of the present invention is to provide a new and improved stand construction for a portable projection screen assembly, which includes a plurality of leg members swingably mounted on the standard, a collar movable axially on said standard between the connection of said leg members to said standard and the end of the standard, bracing links each pivotally secured at each of its opposite ends to one of the leg members and to the collar, and spring means for biasing said leg members to retracted storage position and for retaining the leg members in storage position, the leg members being moved outwardly with respect to the axis of the standard upon application of a tilting force to one of the leg members, and the leg members being automatically moved to retracted storage position and retained in such storage position when the projection screen assembly is raised from a supporting surface.

Another object of this invention is to provide an improved stand construction for a portable projection screen assembly having a plurality of legs pivotally afiixed at one end to a first collar that is fixed on the standard at a dictance from the lower end thereof, a second collar slidably carried on the standard between the first collar and the lower end of the standard, a plurality of bracing links each pivotally connected at one end to the first collar and at the other end to a leg, and spring means operatively connected between the first collar and the legs for normally biasing the legs toward retracted storage position, whereby lifting of the portable projection screen assembly from a supporting surface will permit automatic retraction of the legs to the storage position and retention of the legs in such storage position. Further objects and advantages of this invention will become more apparent hereinafter.

The specific structural details of a preferred embodiment of the invention 'and their mode of functioning 3,315,930 Patented Apr. 25, 1967 will be made most manifest and particularly pointed out in clear, concise and exact terms in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a side elevation view of the portable projection screen assembly of this invention with the supporting legs retracted and with the screen housing disposed in storage position;

FIGURE 2 is a side elevation view of the portable projection screen assembly with the supporting legs extended and with the screen housing disposed in storage position;

FIGURE 3 is an enlarged detail view of the stand construction illustrating the position of the legs as force is applied to one leg to commence movement of all of the legs from the retracted storage position to the standardsupporting position;

FIGURE 4 is an enlarged detail view of the stand construction illustrating the position of the legs intermediate the retracted storage position and the extended standardsupporting position;

storage position;

FIGURE 6 is a detail view similar to FIGURE 5, illustrating the position of the spring when the legs are fully extended to column-supporting position;

FIGURE 7 is an enlarged detail view illustrating the cognection of a leg to the collar fixed on the standard; an

FIGURE 8 is an enlarged detail view taken along the line 8-8 of FIGURE 4 and illustrating the spring operative between a leg and a bracing link.

Referring to FIGURES 1 and 2, there is illustrated a portable projection screen assembly embodying the present invention. The assembly 10 comprises an elongated tubular upright or vertical column 11 which may be square or triangular in cross section.

Movably supported on the upright which is retained in suitable adjusted position on the upright 11 by means of a nipping lever 13 in a conventional manner. The screen housing or screen casing 14 is pivot- .ally carried by the handle '12 and is adapted to be moved about the pivot means on the handle from an upright storage position, wherein the axis of the screen housing is parallel to the axis of standard .11, to a generally horizontal use or picture-exhibiting position, wherein the axis of the screen housing 14 is at substantially right angles to the axis of standard 1 1. Carried within the screen housing 14 is a biased roller upon which the screen is adapted to be supported. As is conventional in use, the screen is unrolled and the bail 16, afiixed on the supporting slat 18, is adapted to be engaged with and supported from the hook portion on top of the extension rod 20. The rod 20 is telescopically received Within the upright 11 and is adapted to be supported in selected adjusted position by means of nipping lever 22 in a conventional manner.

Stand means 24 are provided to support the vertical column 11 in upright use position. The stand means 24 comprise a plurality of legs 26, generally three in number, which are pivoted at their upper ends, as indicated at 28, to an upper leg bracket or collar 30 that is fixed on the upright 11. Slidable on the upright 11 and movable axially thereof is a lower leg bracket or collar 32. Links or braces 34 are each pivotally connected at one end to the lower bracket or collar 32 as indicated at 33. The other end of link 34 is pivoted to a leg member 26, as indicated at 27. The legs 26 are movable between a folded-together or retracted-storage position (shown in FIGURE 1) and a spread-apart or extended standard-supporting position (shown in FIGURE 2).

generally 11 is a handle 12 Referring to FIGURES 3 and 4, there is illustrated sequentially the manner of extending the legs from the retracted position to the column or standard-supporting position. Initially, as best seen in FIGURE 3, the portable projection screen assembly is tilted so that one leg only is bearing upon the supporting surface. The leg 26 is pivoted outwardly away from the standard, causing the annular collar 32 to move downwardly with respect to the standard '11. As the three bracing links 34 are interconnected to one another at collar 32, the movement of one leg 26 will cause the collar 32 to move downwardly on the standard and will cause movement of the three legs simultaneously outwardly toward extended standard-supporting position as seen in FIGURE 4.

Continued application of force will cause the collar 32 to engage stop means provided adjacent the lower end of standard 11. The stop means may comprise an end cap 36 afiixed to the lower end of the standard 11 by a screw 38. The stand means is constructed and arranged such that when collar 32 engages the stop means, the legs 26 will be spread apart to the desired degree so as to provide stable support for the standard 11.

Upon lifting of the portable projection screen assembly from the supporting surface, the legs 26 will be automatically moved toward retracted-storage position, which is shown in FIGURE 1. The legs 26 are comprised of channel members generally U-shaped in cross section. The channel members open inwardly so as to receive the bracing links 34 and, thus, provide a compact assembly for storage.

It will be noted that the legs 26 are pivoted at their upper ends and thus have a natural tendency to move inwardly toward the axis of standard 11 when the legs are off the supporting surface. Further, bracing links 34 are each pivotally connected to the legs 26 below the center of gravity of the legs and the collar 32 is arranged for movement on the standard above a plane passing through each of the pivot pins 27. This arrangement of legs and bracing links provides for gravity closure of the legs 26.

The force of gravity is assisted by spring means provided in the stand construction to facilitate retraction of the legs 26 and to maintain the legs in retracted-storage position. Such spring means preferably comprise a plurality of springs operatively disposed for biasing the legs 26 inwardly toward the standard and for retaining the legs 26 tightly closed in storage position. In the illustrated embodiment of the invention, a spring 40 is positioned between each leg 26 and the collar 30. In addition,'a spring 3-9 is provided between each bracing 7 link 34 and an associated leg 26. If desired, a spring may be provided at each pivot 33 to urge the bracing links 34 inwardly toward the axis of standard 11.

Referring now to FIGURES 4-8, there is illustrated more clearly a presently preferred spring arrangement for biasing the legs toward the closed position and for retaining the legs in such closed position. The legs 26 are rotatably carried about rivet-like pivot pins 28 that are secured in the outwardly extending flange portions 30a of the collar 30. Collar 30 is connected to standard t11 by suitable fastening means, such as screw 31, or a rivet (not shown).

Each coil spring member 40 for biasing an associated leg member 26 inwardly toward retracted position includes spaced-apart c-oil portions 41a and 41b adapted to be positioned and carried on the pivot pin 28 and outwardly projecting arms 42a, 42b and 43. The arms 42a and 42]; extend from each end of the spring 40 and the arm 43, which extends intermediate the coil portions 41a and 41b, is defined by a centrally disposed loop in the wire forming the spring 40. The arm 43 is adapted to engage the exterior of the leg 26 and the arms 42a and 42b of spring 40 are adapted to engage the interior of flange 300 on collar 30. It will be understood that the arms 42a, 42b and 43 of the spring 40 are normally biased in opposite directions away from one another. Thus,

when the legs 26 are raised from a supporting surface, the spring 40 will be positioned as shown in FIGURE 5 so as to bias the legs 26 toward retracted position adjacent to standard 11. The spring has sufiicient force to retain the legs tightly together to provide a compact organization of elements. When a leg is forced outwardly away from the standard 11, spring 40 will be compressed and the arm thereof will be moved generally toward a position illustrated in FIGURE 6.

The spring 39 operatively disposed between each bracing link 34 and an associated leg 26 comprises a coil spring having arms 39a and 3% extending in opposite directions therefrom. The coil portion of the spring is carried on the pivot pin 27 that pivotally joins the bracing link with the associated leg. Leg 39a of the spring is adapted to engage the leg 26 and the arm 3% of spring 39 is adapted to engage the top of the U-shaped or channel-shaped bracing link 34. The spring 39 further assists the movement of the legs toward the closed position and thus effects faster or stronger retraction of the legs on larger size units. If desired, the springs 39 may be omitted from smaller size units.

The operation of the portable projection screen assembly 10 will be summarized briefly. When in storage, the axis of screen housing 14 is disposed parallel to the axis of the standard and the legs of the stand construction are retracted into position adjacent to the standard. For use, a force is applied against one of the legs 26 at an angle to the axis thereof so as to pivot the leg outwardly, causing the collar 32 to move relative to the standard 11, thereby extending the bracing links and, therefore, the three legs against the bias of the springs 39 and 40. The legs 26 are moved simultaneously from the position shown in FIGURE 1 to the position shown in FIGURE 2. The screen can be moved to the use position from the storage position by moving the extension rod 20 outwardly from the standard, pivoting the screen casing 14 to a generally horizontal position, and then extending the screen and fixing the bail 16 to the hook-like end portion of the telescoping extension rod 20.

When it is desired to store the projection screen assembly after use, the bail 16 is removed from the hook portion of the extension rod 20 and the screen is rolled within the screen housing 14. The housing 14 is then rotated from the use position to the storage position and the telescoping rod 20 is lowered into standard 11 to lock the screen housing in storage position. Upon lifting of the portable screen assembly from the supporting surface, the legs are automatically retracted toward the storage position and are retained in the storage position by the cooperation of the springs 39 and 40.

The present invention is characterized by simplicity of design. The unique leg construction permits biased closure of the legs from extended use position to retracted storage position. The gravity closure of the legs is assisted by springs which cooperate with the legs independent from theextension rod to retain the legs in retained storage position. The legs may be simultaneously moved from retracted position to extended position by tilting one of the legs outwardly with respect to the axis of the standard.

While I have described for purposes of illustration a presently preferred embodiment of my invention, it will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In a portable projection screen assembly, an elongated standard; stand means on said standard movable between retracted storage position and standard-supporting position, said stand means including a plurality of legs and pivot means for swingably mounting the legs at their upper ends on said standard at a distance spaced from the lower end thereof, a collar movable axially on said standard between the connection of the legs to the standard and the lower end of the standard, bracing links each pivotally secured at each of its opposite ends to one of the legs and to said collar, first spring means between the legs of the stand means and said standard for biasing said legs to retracted storage position, said first spring means comprising a coil spring carried on the pivot means that swingably secures an end of a leg to the standard, and second spring means between each leg and its associated bracing link for urging the legs to retracted storage position, said stand means being constructed and arranged to be moved to standard-supporting position by application of force to one of the legs upon a supporting surface to pivot same outwardly and being adapted to be moved automatically to retracted storage position when the assembly is raised from the supporting surface.

2. A portable stand construction comprising, in combination: an elongated standard and stand means on said standard movable between retracted storage position and spread-apart, standard-supporting position, said stand means including a plurality of channel-like leg members swingably mounted on a first collar fixed on said standard and spaced from an end thereof, a second collar slidable on said standard disposed between said first collar and the end of said standard, bracing links each pivotally secured at each of its opposite ends to one of the leg members and to the second collar, spring means operative between each of said legs and said first collar for biasing said leg members to retracted storage position, and stop means on the end of the standard for engaging the second collar to limit movement of said second collar, said spring means for biasing the leg members to retracted storage position comprising a coil spring carried on a pivot member that pivotally secures an end of a leg to the first collar, said coil spring including a first arm for engaging said leg and a second arm for engaging said first collar, said leg members being constructed and arranged to be moved to standard-supporting position by application of force against one of the leg members to pivot said leg member outwardly and being adapted to be moved automatically to retracted storage position when the standard is raised from a supporting surface.

3. A portable stand construction adapted to be maintained in an upright position upon a supporting surface comprising, in combination: an elongated standard, a collar fixedly mounted on said standard and leg means movable between retracted storage position and spreadapart, standard-supporting position for supporting the standard, said leg means including a plurality of legs swingably mounted at their upper ends on said standard at a distance from one end thereof, a collar slidable on said standard between said one end and the mounting of said legs on said standard, bracing links each pivotally $ecured at each of its opposite ends to one of the leg members and to the slidable collar, spring means operatively disposed between each of said legs and said fixed collar for normally biasing thelegs to retracted storage position, said spring means comprising a plurality of coil springs, each coil spring including oppositely biased arm members respectively abutting a leg member and said fixed collar for urging the associated legs inwardly toward the standard, said leg means being constructed and arranged to be moved to spread-apart position by tilting one of the legs outwardly with respect to the standard and being adapted to be moved automatically to retracted storage position when the standard is raised from a supporting surface, and a stop member on the standard at the lower end thereof for engaging the collar to limit movement of the collar toward the lower end of the standard.

4. A portable stand construction comprising, in combination, an elongated standard and stand means on said standard movable between retracted storage position and spread-apart, standard-supporting position, said stand means including a plurality of channel-like leg members swingably mounted on a first collar fixed on said standard and spaced from an end thereof, a second collar slidable on said standard disposed between said first collar and the end of said standard, bracing links each pivotally secured at each of its opposite ends to one of the leg members and to the second collar, spring means operative between each of said legs and said first collar for biasing said leg members toward retracted storage position, spring means operative between each leg and its associated bracing link for urging said bracing link toward retracted position, and stop means on the end of the standard for engaging the second collar to limit movement of said second collar, said leg members being constructed and arranged to be moved to standard-supporting position by application of force against one of the leg members to pivot said leg member outwardly and being adapted to be moved automatically to retracted storage position when the standard is raised from a supporting surface.

References Cited by the Examiner UNITED STATES PATENTS 755,043 3/1904 Pike et al 248-171 1,258,518 3/1918 Ankovitz 248-171 X 2,825,518 3/1958 Cooleyet al 248-171 2,899,164 8/1959 Nicholas et a1. 248-171 2,925,979 2/1960 Walker 248-l46 CLAUDE A. LE ROY, Primary Examiner. JOHN PETO, Examiner,

Claims (1)

1. IN A PORTABLE PROJECTION SCREEN ASSEMBLY, AN ELONGATED STANDARD; STAND MEANS ON SAID STANDARD MOVABLE BETWEEN RETRACTED STORAGE POSITION AND STANDARD-SUPPORTING POSITION, SAID STAND MEANS INCLUDING A PLURALITY OF LEGS AND PIVOT MEANS FOR SWINGABLY MOUNTING THE LEGS AT THEIR UPPER ENDS ON SAID STANDARD AT A DISTANCE SPACED FROM THE LOWER END THEREOF, A COLLAR MOVABLE AXIALLY ON SAID STANDARD BETWEEN THE CONNECTION OF THE LEGS TO THE STANDARD AND THE LOWER END OF THE STANDARD, BRACING LINKS EACH PIVOTALLY SECURED AT EACH OF ITS OPPOSITE ENDS TO ONE OF THE LEGS AND TO SAID COLLAR, FIRST SPRING MEANS BETWEEN THE LEGS OF THE STAND MEANS AND SAID STANDARD FOR BIASING SAID LEGS TO RETRACTED STORAGE POSITION, SAID FIRST SPRING MEANS COMPRISING A COIL SPRING CARRIED ON THE PIVOT MEANS THAT SWINGABLY SECURES AN END OF A LEG TO THE STANDARD, AND SECOND SPRING MEANS BETWEEN EACH LEG AND ITS ASSOCIATED BRACING LINK FOR URGING THE LEGS TO RETRACTED STORAGE POSITION, SAID STAND MEANS BEING CONSTRUCTED AND ARRANGED TO BE MOVED TO STANDARD-SUPPORTING POSITION BY APPLICATION OF FORCE TO ONE OF THE LEGS UPON A SUPPORTING SURFACE TO PIVOT SAME OUTWARDLY AND BEING ADAPTED TO BE MOVED AUTOMATICALLY TO RETRACTED STORAGE POSITION WHEN THE ASSEMBLY IS RAISED FROM THE SUPPORTING SURFACE.

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