US3236286A

US3236286A - Portable projection screen

Info

Publication number: US3236286A
Application number: US331998A
Authority: US
Inventors: Robert E Jacobson
Original assignee: Radiant Manufacturing Corp
Current assignee: Radiant Manufacturing Corp
Priority date: 1963-12-20
Filing date: 1963-12-20
Publication date: 1966-02-22
Anticipated expiration: 1983-02-22

Description

Feb. 22, 1966 R. E. JACOBSON PORTABLE PROJECTION SCREEN 2 Sheets-Sheet l Filed Dec. 20, 1963 vEQ,

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United States Patent @hice Patented Feb. 22, 1966 3,236,286 PORTABLE PRSECTIN SCREEN Robert E. Jacobson, Elk Grove Village, ill., assigner to Radiant Manufacturing Corporation, Morton Grove, lll., a corporation of Illinois Filed Dec. 20, 1963, Ser. No. 331,998 1 Cinirn. (Cl. 16u-24) This invention has to do with portable projection screens of the types which have a vertical hollow supporting post, an elongated screen case having a roller mounted tlexible screen therein and pivotally mounted on the supporting post for swinging movement between a vertical position for transportation and storage purposes and a horizontal position for picture exhibiting purposes, and an extension rod slidably mounted in the supporting post and movable between a raised position for supporting the iiexible screen in picture exhibiting position and a lowered position for locking the screen case in its vertical position. A pair of brackets are carried by the supporting post, a plurality of legs are pivotally connected to one of the brackets, and a plurality of links are pivotally connected to the other of said brackets and to the legs to form a collapsible stand for the supporting post, the legs being swingable between a normally extended position (to which they are urged by springs or gravity or both) for engaging the oor and supporting the supporting post in its vertical position for picture exhibiting purposes and a collapsed position for transportation and storage purposes.

Specically, in accordance with this invention and as an object or" this invention, projections are provided on the inner ends of the links in alignment with the supporting post, a plunger is slidably mounted in the supporting post and is adapted to engage the projections. and a spring is arranged in the supporting post between the plunger and the extension rod, 4the spring being inactive when the extension rod is raised from its lowered position to allow extension of the legs to their normally extended position, and the spring being stressed by the extension rod, when the extension rod is moved to its lowered position to lock the screen case in its vertical position, to cause the plunger 'to resiliently press against the projections and resiliently bias the normally extended legs to their collapsed position for causing automatic collapsing of the legs when lifted from the oor and for maintaining the legs in their collapsed position for transportation and storage purposes until the extension rod is raised from its lowered position. Also, a spring, which is relatively weak with respect to the aforementioned spring which is relatively strong, may be utilized for urging the plunger toward the extension rod when the aforementioned relatively strong spring is not stressed by the extension rod, the relatively strong spring .overcoming the force of the relatively weak spring when the relatively strong spring is stressed by the extension rod.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings, in which:

FIG. l is an elevational view of the portable projection screen of this invention raised from the floor and in collapsed position for transportation and storage purposes;

Fl'G. 2 is an elevational view similar to FIG. 1 with the legs extended and resting on the floor and with the screen case released so that it may be swung to a horizontal position for picture exhibiting purposes:

FIG. 3 is an elevational view similar to FIGS. 1 and 2 showing the legs in extended position and resting on the floor but with the screen case locked in vertical position;

FIG. 4 is a horizontal view taken substantially along the line 4 4- of FIG. 2;

FIG. 5 is an enlarged vertical sectional view, with parts broken away, taken through the portable projection screen and with the legs of the projection screen collapsed and the screen case locked as in FIG. 1;

FIG. 6 is an enlarged vertical sectional view similar to FIG. 5 but showing the legs extended and the screen case released as in FIG. 2; and

FIG. 7 is an enlarged vertical sectional view similar to FIGS. 5 and 6 but showing the legs extended and the screen case locked as in FIG. 3.

Referring rst to FIGS. l to 4 the portable projection screen of this invention is generally designated at 10. It includes a normally vertically arranged hollow supporting post 11 upon which is slidably mounted a handle member 12. The handle member 12 is provided with a double-acting nipping lever 13 which may be of the kind disclosed in Nicholas Patent No. 2,812,808. When the nipping lever 13 is depressed, the handle member 12 may be adjustably positioned along the supporting post 11 and when the nipping lever 13 is released, the handle member 12 is locked in position on the supporting post 11 against movement in either direction. The handle member 12 pivotally carries a bracket 14 which in turn is secured to a screen case 15, the screen case 15 being swingable to a vertical position for transportation and storage purposes and being swingable to a horizontal position for picture exhibiting purposes. The screen case 15 is provided With end-caps 16 and a roller mounted flexible screen is carried within the screen case 15. The free end of the flexible screen is provided with a suspension slat 1-7 xhaving a bail 18 for withdrawing the exible screen from the screen case when the screen case is in its horizontal position for picture exhibiting purposes.

Slidably mounted in the hollow supporting post 11 is an extension rod 19 having on its upper end a hook member 20 which is provided with a detent 21 for receiving the bail 13 in picture exhibiting position when the extension rod 19 is raised, and with a locking member 22 engaging one of the end-caps 16 of the screen case 15 when the extension rod 19 is moved to a lowered position for locking the screen case in its vertical position for transportation and storage purposes. The extension rod 19 extends upwardly from the supporting post 11 through a cap 23 suitably secured in place on the supporting post` Below the cap 23 there is provided a double-acting nipping lever 24 which is urged into gripping relation with the extension rod 19 by a spring 25, as shown more clearly in FIGURES 5 to 7. The nipping lever 24 abuts and pivots in an opening in the supporting post to prevent downward movement of the extension rod 19 and it abuts and pivots about a projection 26 in the supporting post to prevent upward movement of the extension rod 19. When, however, the nipping lever 24 is manually manipulated against the action of the spring 25, the extension rod 19 is released and may be moved upwardly and downwardly.

An upper bracket 36 is slidably mounted on the supporting post 11 and a plurality of legs 32 are p-ivotally connected thereto by means of pins 33. The lower ends of the legs 32a are adapted to rest upon the iloor 37 for supporting the supporting post and, hence, the projection screen in vertical position when the legs 32 are in their extended position. Another bracket 31 is rigidly secured to the bottom of the supporting post 11 and one end of a plurality of links 34 are pivotally connected to the bracket 31 by pins 35 while the other ends of the links 34 are pivotally connected to the legs 32 by pins 36. Thus, the legs 32 and the links 34 in conjunction with the

brackets

30 and 31 form a collapsible stand for the projection screen. The legs 32 may be swung to a collapsed position as illustrated in FIG. 1 and to an extended position as illustrated in FIGS. 2 and 3. The legs normally assume the extended position, they being urged to this position by the weight of the legs or by suitable springs (not shown) carried by the pins 36 and engaging the legs 32 and links 34.

As seen more clearly in FIGS. 5 to 7, the inner ends of the links 34 are provided with projections 41B which are in alignment with the supporting post 11. These projections are adapted to be engaged by a head 41 on a plunger 42 slidably mounted in the lower end of the supporting post 11. The plunger 42 is also provided at its upper end with a head 43, and a relatively weak spring 44 engaging the head 43 operates to resiliently bias the plunger 42 upwardly toward the extension rod 19. A relatively strong spring 45 is interposed between the head 43 on the plunger 42 and a head 46 on the bottom of the extension rod 19.

When the extension rod 19 is raised from 4its lowered position as a result of manipulation of the nipping lever 24 to release the hook member 2i) from the screen case 15, as illustrated in FIGS. 2 and 6, the relatively strong spring 45 is inactive, the relatively weak spring 44 raises the plunger 42 and the legs 32 automatically swing to their extended position as illustrated in FIGS. 2 and 6. Thus, the portable projection screen may be supported by the legs 32 on the floor 37 for picture exhibiting purposes.

` When the projection screen is to be transported or stored,

v member 20 to lock the screen case 15 in its vertical position. When this `is done, the legs 32 are still extended and engaging the floor 37 as illustrated in FIGS. 3 and 7. By moving the extension rod 19 to its lowered position, the extension rod stresses the relatively strong spring 45 to resiliently urge the plunger 42 into engagement with the projections 40 on the inner ends of the links 34. However, since the legs 32 are engaging the oor 37, they remain in their extended position due to the weight of the projection screen thereon, this condition being illustrated in FIGS. 3 and 7. When, however, the projection screen is lifted from the floor 37, as illustrated in FIGS. l and 5, the stressed relatively strong spring 45 overcomes the force of the relatively weak spring 44 to cause the plunger 42 to push the projections 40 downwardly and, hence, automatically move the legs 32 to their collapsed position, as illustrated in FIGS. 1 and 5. The relatively strong spring 45 maintains the legs 32 in their collapsed position for transportation and storage purposes so long as the extension rod 19 is maintained in its lowered position for locking the screen case in its vertical position. To set 45 moves the extension rod 19 upwardly from its lowered position, as illustrated in FIGS. 2 and 6. This unlocks the screen case 15 and renders the relatively strong spring 45 ineffective so that the plunger 42 moves upwardly and the legs 32 move automatically outwardly to their normal extended position.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope ofthe appended claim.

I claim as my invention:

In a portable projection screen having a vertical hollow supporting post, an elongated screen `case having a roller mounted flexible screen therein and pivotally mounted on the supporting post for swinging movement between a vertical position for transportation and storage purposes and a horizontal position for picture exhibiting purposes, an extension rod slidably mounted in the supporting post and movable between a raised position for picture exhibiting purposes and a lowered position for locking the screen case in its vertical position, a pair of brackets carried by the supporting post, a plurality of legs pivotally connected to one of the brackets, and a plurality of links pivotally connected to the other of the brackets and to the legs, said legs being swingable between a normally extended position for engaging the floor and supporting the supporting post in its vertical position for picture exhibiting purposes and a collapsed position for transportation and storage purposes, the improvement comprising, projections on the inner ends of the links in alignment with the supporting post, a plunger slidably mounted in the supporting post and adapted to engage the projections, a relatively weak spring in the supporting post normally urging the plunger away from the projections, and a relatively strong spring in the supporting post between the plunger and the extension rod which is inactive when the extension rod is raised from its lowered position to allow extension of the legs to their normally extended position and which is stressed by the extension rod when the extension rod is moved to its lowered position to lock the screen case in its vertical position to overcome the relatively weak spring and cause the plunger to resiliently press against the projections and resiliently bias the normally extended legs to their collapsed position for causing automatic collapsing of the legs when lifted from the floor and for maintaining the legs in their collapsed position until the extension rod is raised from its lowered position.

References Cited by the Examiner UNITED STATES PATENTS 1,287,365 12/1918 Livingston 248--169 2,750,141 6/1956 Tobias 248-171 2,964,106 12/1960 Nicholas 160--24 3,164,348 1/1965 Armstrong 248-171 HARRISON R. MOSELEY, Primary Examiner.

D. L. TAYLOR, Assistant Examiner.