US1915944A - Projection screen - Google Patents

Description

June 27, 1933. H. NAGEL PROJECTION SCREEN Filed Feb. 18, 1932 2 Sheets-Sheet 1 June 27, 1933. H NAGEL 1,915,944

PROJECTION SCREEN Filed Feb. 18, 1932 2 Sheets-Sheet 2 Patented June 27, 1933 UNITED STATES PATENT OFFICE HUGO NAGEL, OF LONDON, ENGLAND, ASSIGNOR TO ROBERT FORGIE HUNTER AND ARTHUR BLACKBURN, BOTH OF LONDON, ENGLAND PROJECTION SCREEN Application filed February 18, 1932, Serial No.

This invention relates to improvements in projection screens of the roller blind type and is more particularly concerned with improvements in and connected with the stretching device for holding the screen in extended position.

end is attached to a member which in the rolled up position of the screen serves as the lid of the box, the stretching device is formed of a pair or pairs of pivoted links, one pair preferably being disposed at each end of the screen with one link of each pair attached to the box and the other hinged to the lid. To the link or each link attached to the box is pivoted one end of a strut, the other end of which is guided in a slotted guide in the box, a spring or springs being attached to the box and to the guided end of the strut or struts. The spring or springs acts or act assist in holding the screen in extended position or to counteract the spring of the roller blind.

A modification of the stretching device comprises a form of lazy tongs attached at one end to the base and at the other to the lid, one arm of the lazy tongs being slidable in a slotted guide in the base and having attached thereto a, spring assisting to hold the screen in extended position and opposing the closing of the lid.

In a still further embodiment of the invention employing a construction of stretching device composed of pivoted links attached at each end to the'base and to the lid, the link attached to the lid is extended beyond its pivot with the other link and there is attached to the extended portion a spring anchored at its other end say to the base of the box and acting as before in a sense contrary to the spring of the roller blind.

The invention is illustrated in the accom- 593,724, and in Great Britain April 16, 1931.

panying drawings in which Fig. 1 is a perspective view of the projection screen in closed position, Figs. 2 and 3 illustrate one embodiment in which Fig. 2 is a rear view of the screen with the container in section and Fig. 3 an end View of the screen. Figs. 4 and 5 illustrate two further embodiments of the invention each figure showing the rear side of the screen.

Referring to the drawings, A is the box or container for the screen B which is adapted to be wound on and unwound from a spring roller C mounted in the box or container A, the screen being attached at its other end to a support D which in the present instance constitutes the lid of the box when the screen is closed. A guide pin E on the container coacts with a guide passage F in the lid D and a spring pressed catch H of known type engaging the pin serves to hold the box closed. A stretching devicedenoted by G serves to hold the screen in extended position. Except as regards certain details the construction so far described is similar to that described in my prior Patent No. 1,897,273 issued February 14, 1933.

In screens of this type as hitherto designed it is diflicult to open the box and extend the screen without assistance as the spring of the roller resists eflort made to stretch the screen. It is only possible to erect the screen by holding the box while pulling up the lid.

This disadvantage is avoided in accordance with the present invention by providing in association with the stretching device G a spring or springs acting in a direction contrary to the spring of the roller thereby facilitating the opening and closing of the screen.

Referring to the embodiment illustrated in Figs. 2 and 3 the stretching device G is formed of pairs of pivoted links 9, 9' one pair disposed at each end of the screen with one link g of each pair attached to the box A and the other hinged to the lid D. To each link 9 attached to the box is pivoted at 'm one end of a strut n the other end of which is fitted with a roller 0 slidable in a slotted guide p mounted in the bottom of the box. Springs 1' anchored at one end to the box and at the other to the guided end of the strut it serve to assist in extending the stretching device G and in holding the screen in extended position against the action of the spring of the roller blind. The springs r and the spring of the roller blind are designed to balance one another more or less so that the screen can be extended with the assistance of the springs 1" against the action oi the roller spring. Preferably the arrangement is such that the maximum extension of the springs '1' has taken place prior to the closure of the lid of the box so that the roller spring is slightly the stronger as the lid reaches the box and will close of its own accord and will be engaged properly by the catch.

In the modification shown in Fig. 4 the link 9' of the stretching device attached to the lid is extended at 9 beyond its pivot with the link 7 and the spring 7' is attached to this end and to the base of the box acting in a sense contrary to the spring of the roller blind.

In the embodiment shown in Fig. 5 the stretching device comprises a form of lazy tongs attached at one end to the base and at the other to the lid one arm 9 of the lazy tongs being fitted with a roller 0 slidable in a slotted guide p mounted in the bottom of the box. spring 1 attached at one end to the box and attached to the roller 0 at the other end, assists in holding the screen in extended position and opposes the closin of the lid due to the spring of the roller blind.

I claim 1. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within the sides of said box, a cover for said box, a projec tion screen attached to said roller and to said cover and spring means, located within the sides of said box and acting contrary to the spring of said spring controlled roller, for serving to control the opening and closing movement of the screen.

2. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within the sides of said box, a cover for said box, a projection screen attached to said roller and to said cover, means for stretching said screen, and spring means, located permanently within the sides of said box and acting contrary to the spring of said spring controlled roller, for serving to control the opening and closing movement of the screen.

3. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen attached to said roller and to said cover, means for stretching said screen, said means comprising a pair of pivoted links one pivoted to the box and the other pivoted to the cover, a guide in said box and a strut extending between the link pivoted to the box and said guide, and a spring connected to the strut and to said box and controlling the movement of said strut in said slotted guide, said spring acting contrary to the spring of the roller.

4. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen Wrapping said roller and attached to said cover, means for stretching said screen, said means comprising a lazy tongs device con necting the cover and the box, a-guide in the box for one end of said lazy tongs device and a spring anchored to the box and to said end, sald spring acting to resist collapse of said lazy tongs and acting contrary to the spring of the roller.

5. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen wrapping said roller and attached to said cover, means for stretching said screen, said means including a pair of links one pivoted to the cover and the other to the box and pivoted to one another and a spring anchored at one end to the link pivoted to the cover and at the other to the box and acting contrary to the spring of the roller.

In testimony whereof I have signed my name to this specification.

HUGO NAGEL.

"DISCLAIMER 1,915,944.Hugo Nagel, London, England. PROJECTION SCREEN. Patent dated June 27, 1933. Disclaimer filed June 7, 1934, by the assignees, Arthur Blackburn and Robert Forgie Hunter. Hereby disclaim from claims 1 and 2 of said Letters Patent any structure wherein the entire spring means acting contrary to the spring of the spring-controlled roller is not located Wholly within the sides of the box when the screen is open.

[Oflicial Gazette July 10, 1934.]

at the other to the guided end of the strut it serve to assist in extending the stretching device G and in holding the screen in extended position against the action of the spring of the roller blind. The springs r and the spring of the roller blind are designed to balance one another more or less so that the screen can be extended with the assistance of the springs 1" against the action oi the roller spring. Preferably the arrangement is such that the maximum extension of the springs '1' has taken place prior to the closure of the lid of the box so that the roller spring is slightly the stronger as the lid reaches the box and will close of its own accord and will be engaged properly by the catch.

In the modification shown in Fig. 4 the link 9' of the stretching device attached to the lid is extended at 9 beyond its pivot with the link 7 and the spring 7' is attached to this end and to the base of the box acting in a sense contrary to the spring of the roller blind.

In the embodiment shown in Fig. 5 the stretching device comprises a form of lazy tongs attached at one end to the base and at the other to the lid one arm 9 of the lazy tongs being fitted with a roller 0 slidable in a slotted guide p mounted in the bottom of the box. spring 1 attached at one end to the box and attached to the roller 0 at the other end, assists in holding the screen in extended position and opposes the closin of the lid due to the spring of the roller blind.

I claim 1. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within the sides of said box, a cover for said box, a projec tion screen attached to said roller and to said cover and spring means, located within the sides of said box and acting contrary to the spring of said spring controlled roller, for serving to control the opening and closing movement of the screen.

2. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within the sides of said box, a cover for said box, a projection screen attached to said roller and to said cover, means for stretching said screen, and spring means, located permanently within the sides of said box and acting contrary to the spring of said spring controlled roller, for serving to control the opening and closing movement of the screen.

3. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen attached to said roller and to said cover, means for stretching said screen, said means comprising a pair of pivoted links one pivoted to the box and the other pivoted to the cover, a guide in said box and a strut extending between the link pivoted to the box and said guide, and a spring connected to the strut and to said box and controlling the movement of said strut in said slotted guide, said spring acting contrary to the spring of the roller.

4. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen Wrapping said roller and attached to said cover, means for stretching said screen, said means comprising a lazy tongs device con necting the cover and the box, a-guide in the box for one end of said lazy tongs device and a spring anchored to the box and to said end, sald spring acting to resist collapse of said lazy tongs and acting contrary to the spring of the roller.

5. A projection screen comprising in combination with a box for said screen a spring controlled roller mounted within said box, a cover for said box, a projection screen wrapping said roller and attached to said cover, means for stretching said screen, said means including a pair of links one pivoted to the cover and the other to the box and pivoted to one another and a spring anchored at one end to the link pivoted to the cover and at the other to the box and acting contrary to the spring of the roller.

In testimony whereof I have signed my name to this specification.

HUGO NAGEL.

"DISCLAIMER 1,915,944.Hugo Nagel, London, England. PROJECTION SCREEN. Patent dated June 27, 1933. Disclaimer filed June 7, 1934, by the assignees, Arthur Blackburn and Robert Forgie Hunter. Hereby disclaim from claims 1 and 2 of said Letters Patent any structure wherein the entire spring means acting contrary to the spring of the spring-controlled roller is not located Wholly within the sides of the box when the screen is open.

[Oflicial Gazette July 10, 1934.]

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