US3568751A

US3568751A - Large motion picture screen rolling-up equipment

Info

Publication number: US3568751A
Application number: US784365A
Authority: US
Inventors: Sasuke Takahashi
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-10-12
Filing date: 1968-12-17
Publication date: 1971-03-09
Anticipated expiration: 1988-03-09

Abstract

Large motion picture projection screen tubular rollup and support mechanism characterized by a rigid but lightweight hollow tubular outer shaft of screen width and a longer rigid inner supporting shaft bearing supported at opposite protruding ends and spaced centrally within the outer shaft by means of a pair of spacing support rings. The rings and the two shafts are so constructed and relatively arranged as to permit the inner shaft to flex under a supporting load in an independent manner which is not transmitted to the outer shaft to which the screen per se is attached, thereby maintaining the screen in a smooth, undistorted manner free of undesirable, abnormal light-reflecting slack or wrinkles when in the extended open screen condition.

Description

United States Patent Sasuke Takahashl [72] Inventor No. 32/11, Yasunakacho-ti-chome, Yao, Osaka-Fu, Japan [21] Appl. No' 784,365 [22] Filed Dec. 17, 1968 [45] Patented Mar. 9, 1971 [32] Priority Oct. 12, 1968 [33] Japan [31] 43/74393 [54] LARGE MOTION PICTURE SCREEN ROLLING-UP EQUIPMENT 4 Claims, 7 Drawing Figs.

[52] U.S. Cl... 160/238 [51] Int. Cl A47g 05mg, A47h 01/00 [50] Field olSearch 160/23, 24, 238

[56] References Cited UNITED STATES PATENTS 2,098,105 11/1937 Nye 160/23 2,894,572 7/1959 Nelson l60/l33X 3,207,206 9/1965 Braddon et al. l60/24 3,228,455 l/l966 Jacobson 160/24 Primary Examiner-Peter M. Caun Attorney-Wenderoth, Lind & Ponack ABSTRACT: Large motion picture projection screen tubular rollup and support mechanism characterized by a rigid but an independent manner which is not transmitted to the outer shaft to which the screen per se is attached, thereby maintaining the screen in a smooth, undistorted manner free of undesirable, abnormal lightreflecting slack or wrinkles when in the extended open screen condition.

PATENTEDMAR elsn 3.568.751

INVEN'H )R 6 a 6 6' SASUKE TAKAnAsu r, 0 I

MM/m,

ATTORNEY ILAliGlE MGTEQN PHCTURE SQREEN lhGLlLlNG-lll EQUEPMENT in the case of a large motion picture projection screen to be hung on the wall or from the ceiling, a rolling-up tube is usually supported at its both ends. Accordingly, its central part is apt to sag slightly by its own weight and by the weight of the screen, due to which there arises a slight wavelike slack on the surface of the screen when the screen is unrolled. Such a slack of the screen produces abnormal reflected light when a picture is projected thereon, which results in uneven reflection of the image on the screen. Moreover, it gives bad effect on the maintenance of the screen if the screen is rolled up in a slack condition.

As'a means to overcome the above disadvantages, it has hitherto been known to increase the thickness and diameter of the rolling-up tube. However, this method has the, disadvantage that total weight of the screen increases inevitably and this produces an adverse effect on the stability of the screen when it is hung on the screen or from the ceiling. Moreover, the cost of the screen increases.

The present invention aims at eliminating above-mentioned disadvantages by producing a new rolling up equipment which is light in weight and yet causes no sagging of the rolling-up tube.

The large motion picture screen rolling-up equipment of the present invention isrcharacterized by preparing a supporting shaft with a pair of supporting rings fixed thereon in a symmetrical position, inserting the supporting shaft into a hollow rolling-up tube, loosely connecting the rolling-up tube and the supporting rings with stoppers in order to make the rolling-up tube and the supporting shaft turn together, making the supporting rings divide whole load to be given onto the rolling-up tube in half, whereby maintaining the balance of the rolling-up tube while preventing it from sagging.

The invention will now be described with particular reference to the accompanying drawings, wherein thereof, and in which:

FlG. l is a longitudinal vertical cross-sectional view to show one embodiment of the present invention;

HG. 2 is a cross-sectional view similar to FIG. 1 of the equipment of the present invention, in which an example of sag induced upon the inner supporting shaft is shown;

Flt 3 and FIG. 4 are respectively magnified vertical crosssectional views taken longitudinally to show the important part of the equipment of the present invention;

MG. 5 and HG. 6 are respectively transverse vertical crosssectional side views of FIG. 3 and FlG. AND

FlG. 7 is a front view to show the situation in which a large motion picture screen with the equipment of the present invention is unrolled for projection use.

A rolling-up tube l is provided to roll up and unroll a motion picture screen 2. The length of the tube 1 corresponds to the width of the screen 2. The rolling-up tube 1 is a straight, thin, round, light metal tube. A supporting shaft 4 with a pair of supporting

rings

3,, 3 fixed thereon in a symmetrical position is inserted into the rolling-up tube 1. Stoppers or fastening means 5, 5 which are loosely fixed on the rollingup tube 1 are respectively screwed into appropriate part of the supporting

rings

3, 3, which have slight peripheral clearance in such a way as the supporting

rings

3, 3 can incline or cant slightly against the internal surface of the rolling-uptube l in accordance with any possible sag of the supporting shaft 4. Both ends of the supporting shaft 4 are held by bearings h, 8.

The relation between the external surface of the supporting ring 3. and the internal surface of the rolling-up tube i may take one of the following two forms. One is that, as shown in FIG. 4 and HG. s, where the external surface of the supporting ring 3 is closer fitting having rounded peripheral side edges, and such peripheral edge closely contacts the internal surface of the'rolling-up tube l. The other is that, as shown in FIGS. 3 andS, a very slight gap 7 is left between the external surface of the supporting ring 3 and the internal surface of the rolling-up tube 1.

The best position for loosely connecting the supporting

rings

3, 3 with the rolling-up tube 1 is about one-fourth inward from both ends of the rolling-up tube It.

The rotation of the supporting shaft 4} is conveyed to the rolling-up tube 1 through the supporting

rings

3, 3. At the points where the supporting

rings

3, 3 are loosely connected with the rolling-up tube 1, the radial distance between the rolling-up tube 1 and the supporting shaft is always kept unchanged whichever direction the supporting shaft 4 may turn. Accordingly, regardless of any change in the relation of distance between the remaining part of the rolling-up tube 1 and its counter part of the supporting shaft 4 there is no change in the outward appearance of the rolling-up tube 1. Thus, there is no fear that upon rotation of the supporting shaft 4, both ends of the rolling-up tube 1 might tend to move in opposite up and down directions from each other, like the movement of a balance beam.

Even if the supporting shaft 4 may sag extremely in such a way as shown in FIG. 2, the supporting

rings

3, 3 divide whole load to be given onto the rolling-up tube 1 in half and each center of gravity falls on one point of the external surface of the supporting ring 3, unless the internal surface of the rollingup tube l comes to contact with the supporting shaft 4 at the center and both ends of the rolling-up tube 11. Thus, the rolling-up tube 1 always maintains balance with these supporting rings serving as fulcrums and it does not sag at all.

A large motion picture screen fixed to the rolling-up tube 1 can be rolled up or unrolled very smoothly. This arrangement permits the use of a light metal for the rolling-up tube 1 and never causes sag or a movement similar to a balance beam. Accordingly, no slack arises on the surface of the screen when the screen is unrolled and no abnormal reflected light is produced when a picture is projected thereon. Thus, it is possible to obtain a clear image without uneven reflection. It is also an apparent fact that the screen is given no bad effect when it is retractively rolled up and stored for next use.

Such being advantages of the present invention, the applicant believes that the present invention is a very significant invention.

When bringing the present invention into operation, it is of course possible to change the design of the equipment to the extent which does not deviate from the spirit of the present invention.

I claim:

1. For use with rollable and unrollable extendable flexible screen and sheet material, such as large motion picture projection screens, improved rollup and in-use support apparatus comprising, in combination:

a. a rigid, hollow outermost tubular shaft having a longitudinal axis and having a flexible sheet material attached for rolling and unrolling thereon;

. a smaller diameter inner supporting shaft of longer length than and initially disposed generally concentrically with said hollow shaft, and having opposite ends projecting from opposite ends of said hollow shaft with said projecting ends adjacent the hollow shaft bearingly supported on external support means;

c. a pair of spacing support ring members embracingly connected to the outer periphery of said inner shaft and extending radially essentially for contact with and special attachment to and for rotation with said outer shaft;

d. fastening means specially fastening said rings, with attached inner shaft, in symmetrical fashion to and inwardly from the opposite ends of said hollow shaft a sufficient and substantial distance relative to the overall length thereof so that the unwinding and in-use tension as normally imparted to the screen or sheet material is divided approximately in half by said rings, and absorbed by the respective shafts in a manner not to distort the hollow outer shaft; and

c. said rings and fastening means being of a size and construction so that their special attachment transversely to the hollow shaft permits the rings to incline and cant slightly relative to the inner periphery and longitudinal axis of said hollow shaft, and to permit the inner shaft to flex throughout its length responsive to the application of a tension of the aforesaid character, without transmitting said flexing or any adverse distortion to the hollow outer shaft, thereby enabling the maintaining of the attached flexible sheet material or screen in a smooth undistorted, wrinkle-free manner in it extended use condition.

2. The apparatus as defined in claim 1 wherein the spacingsupport rings are of predetermined width and have an outer diameter size sufficiently less than the inside diameter of said hollow shaft, whereby they are permitted, together with said fastening means which are fastening pins projecting generally radially between said rings and hollow shaft with outer ends of said fastening pins generally flush mounted in a wall portion of said hollow shaft, said hollow shaft having clearance apertures being of a size sufficient to enable the predetermined size rings, as mounted upon the inner shaft, to incline and cant under the stated conditions.

3. The apparatus as defined in claim 1 wherein the spacing support rings are of a predetermined width and have an outer diameter size corresponding essentially to the inside diameter of said hollow shaft, said outer diameter of said rings being rounded adjacent the outer periphery and on both adjacent sides thereof, whereby they are permitted, together with said fastening means which are fastening pins projecting generally radially between said rings and hollow shaft with outer diameter of said hollow shaft, said hollow shaft having clearance apertures for receiving said pins, and said clearance apertures being of a size sufficient to enable the predetermined size rings, as mounted upon the inner shaft, to incline and cant under the stated conditions.

4. For use with rollable and unrollable, extendable flexible screen and sheet material, such as large motion picture projection screens, improved rollup and in-use support apparatus comprising in combination:

a. a pair of generally coaxial supporting shafts including an outer hollow tubular shaft of a width corresponding to the flexible sheet material rollingly supported thereon, and an inner shaft of greater length having opposite ends projecting from-the corresponding opposite ends of said hollow shaft and bearingly supported on external support means adjacent the opposite ends of said hollow shaft;

b. a pair of spacing support rings embracing said inner shaft in symmetrical relation relative to an inwardly from the opposite ends of and extending radially essentially for contact with and special attachment to said outer shaft, a distance relative to the overall length thereof, so that the unwinding and in-use tension as normally applied to the screen or sheet material attached to the outer shaft is divided approximately in half by said rings and absorbed by the respective shafts in a manner not to warp and distort the hollow outer shaft;

c. means to facilitate attachment of said rings in a transverse manner to said hollow shaft; and

d. said rings being of a size and construction and by the means to facilitate their special attachment to said hollow shaft, enable said rings to incline and cant to a limited extent relative to the inner periphery and longitudinal axis of said hollow shaft, to permit the inner shaft to flex throughout its length responsive to the application of the aforesaid tension without transmitting said flexing or any adverse distortion to said hollow outer shaft, thereby enabling the maintaining of the flexible sheet or screen material in a smooth wrinkle-free undistorted manner in its extended use condition.

Claims

1. For use with rollable and unrollable extendable flexible screen and sheet material, such as large motion picture projection screens, improved roLlup and in-use support apparatus comprising, in combination: a. a rigid, hollow outermost tubular shaft having a longitudinal axis and having a flexible sheet material attached for rolling and unrolling thereon; b. a smaller diameter inner supporting shaft of longer length than and initially disposed generally concentrically with said hollow shaft, and having opposite ends projecting from opposite ends of said hollow shaft with said projecting ends adjacent the hollow shaft bearingly supported on external support means; c. a pair of spacing support ring members embracingly connected to the outer periphery of said inner shaft and extending radially essentially for contact with and special attachment to and for rotation with said outer shaft; d. fastening means specially fastening said rings, with attached inner shaft, in symmetrical fashion to and inwardly from the opposite ends of said hollow shaft a sufficient and substantial distance relative to the overall length thereof so that the unwinding and in-use tension as normally imparted to the screen or sheet material is divided approximately in half by said rings, and absorbed by the respective shafts in a manner not to distort the hollow outer shaft; and e. said rings and fastening means being of a size and construction so that their special attachment transversely to the hollow shaft permits the rings to incline and cant slightly relative to the inner periphery and longitudinal axis of said hollow shaft, and to permit the inner shaft to flex throughout its length responsive to the application of a tension of the aforesaid character, without transmitting said flexing or any adverse distortion to the hollow outer shaft, thereby enabling the maintaining of the attached flexible sheet material or screen in a smooth undistorted, wrinkle-free manner in it extended use condition.

2. The apparatus as defined in claim 1 wherein the spacing-support rings are of predetermined width and have an outer diameter size sufficiently less than the inside diameter of said hollow shaft, whereby they are permitted, together with said fastening means which are fastening pins projecting generally radially between said rings and hollow shaft with outer ends of said fastening pins generally flush mounted in a wall portion of said hollow shaft, said hollow shaft having clearance apertures being of a size sufficient to enable the predetermined size rings, as mounted upon the inner shaft, to incline and cant under the stated conditions.

4. For use with rollable and unrollable, extendable flexible screen and sheet material, such as large motion picture projection screens, improved rollup and in-use support apparatus comprising in combination: a. a pair of generally coaxial supporting shafts including an outer hollow tubular shaft of a width corresponding to the flexible sheet material rollingly supported thereon, and an inner shaft of greater length having opposite ends projecting from the corresponding opposite ends of said hollow shaft and bearingly supported on external support means adjacent the opposite ends of said hollow shaft; b. a pair of spacing support rings embracing said inner shaft in symmetrical relation relative to an inwardly from the opposite ends of and extending radially essentially for contact with and special attachment to said outer shaft, a distance relative to the overall length thereof, so that the unwinding and in-use tension as normally applied to the screen or sheet material attached to the outer shaft is divided approximately in half by said rings and absorbed by the respective shafts in a manner not to warp and distort the hollow outer shaft; c. means to facilitate attachment of said rings in a transverse manner to said hollow shaft; and d. said rings being of a size and construction and by the means to facilitate their special attachment to said hollow shaft, enable said rings to incline and cant to a limited extent relative to the inner periphery and longitudinal axis of said hollow shaft, to permit the inner shaft to flex throughout its length responsive to the application of the aforesaid tension without transmitting said flexing or any adverse distortion to said hollow outer shaft, thereby enabling the maintaining of the flexible sheet or screen material in a smooth wrinkle-free undistorted manner in its extended use condition.