US2546299A - Portable projection screen - Google Patents

Description

March 27, 1951 J.' DUY MAl ET AL 2,546,299

PORTABLE PROJECTION SCREEN Filed July 18, 1946 2 Sheets-Sheet 1 I I I L. J. DU MAlS ET AL PORTABLE PROJECTION SCREEN March 27, 1951 2 Sheets-Sheet 2 Filed July 18, 1946 3i IHIHIIIIIIIIIH Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE,

PORTABLE PROJECTION SCREEN Leo J. Du Mais, Chicago, and John T. Heck,

El'mh-u-rst, Ill., assignors to Da-Lite Screen 00.,

Inc Chicago, 111., a corporation Application July 18 1946, Serial No. 684,578.

(01. ISO-+24) 6 Claims. 1.

Our invention relates to portable screens, especially designed for projection of moving pictures or other transparencies;

A particular object of our invention is to provide a portable stand 'or support for a screen in combination with a screen and its housing, all of which are capable of folding into a compact unit. for convenience in storage and portability.

Another object is to provide a device of the type referredto, which may be inexpensively fabricated out ofa relatively small number of, sim ple parts; which may be largely of sheet metal, to produce a strong, rigid and attractive unit, which will be simple in operation and of light weight;

Still another object is'to provide such a device which may be quickly and easily assembled and demounted without tools.

Various otherobjects and advantages will probably suggest themselves to those skilled in the art, as the description proceeds.

Referring now to the drawings forming part of thisspecification and illustrating a preferred embodiment of our invention, Fig; lisa perspective view of a screen and stand combination embodying our invention, the device being set upin position for use, the screen being shown extended in dot dash lines;

Fig. 2' is a fragmentary vertical sectional view through a mid portion or the support or stand;

Fig. 3' is a sectional view taken substantially alongthe line 3-3 of Fig. 2;

Fig; 4 is a perspective view showing details of parts shown in- Fig. 2;

Fig. 5 is-a fragmentary perspective view of" the end of a supporting leg forming an element of ouninvention;

Fig. 6::is a perspective viewof a locking or retaining member-forming another element of our invention;

Fig. 7 is anexploded perspective view showing detailsof a telescopic support forming a feature of our invention;

Fig. 8- isa fragmentary vertical elevation with parts broken away, showing retention of the screen by the pedestal when the parts are collapsed as for carrying;

Fig. 9* is a fragmentary vertical sectional view of a portion ofv the telescopicsupport;

Fig. 10 is a fragmentary vertical view; partly in elevation and partlyin section, showing attachment of the legs to the telescopic support;

Fig. 11- is a partial sectional view of the device, and: r

Fig. 1-2 isatransverse sectional view of one 2 of the pedestal legs forming, part of our invention.

The screen H), which may be of any suitable or known type is housed within a casing 12, which may be of circular or polygonal cross section, octagonal in the form shown. The casing is provided with end caps l5, which are preferably dished in the central portion thereof. Surrounding the dished portion is a bevelled seat with a pair of opposite punctures for retaining a suitab e disc I6 for imparting; anattractive finish to the end of the casing l2 and concealing the end of the reel R; journaled' in the end caps.

Intermediate the ends of the casing I2 is a center strap ll having a boss [8 through which extends a retaining member 20 such as a rivet, screw or the like for swivellymounting the screen and its casing on a U-'-shaped bracket 22, the leg portion 23- of said bracket being perforated whereby it is slideably mounted on a pedestal or stand indicated generally-by the numeral 25. Swivelly attached to the free ends of the leg portion 23 of the bracket 22 as by rivets 26 is a handle 21. Bysuch an arrangement the handle may, when the device is stored or shipped, be swung into a position conserving space, as shown dotted in Fig. 3. This handle is so positioned that the device will be substantially balanced when carried by the handle. Pivoting the ham-- dle enables the weight of the screen to adjust itself in carrying; it also facilitates setting up the screen, when the handle may be grasped to steady the support.

Secured to the bottom end of pedestal 25 as by a screwor the like is a collar 30 for retaining a tripod 3!. The tripod consists of legs 32-, which are connected to the collar 30 by means of arms 33 and at their upper extremities are fastened as by rivets or the like to ears 34 formed on a bracket 35 which is slideable on the pedestal 25. The ears 34 are preferably formed at an angle of degrees at their upper edges to provide maximum rigidity. The arms are so pivoted to the legs that the weight is directly carried on the arms and transferred to the legs, which causes the overlying upper portion of the legs to rest snugly on the 45- degree angle of the ears.

As seen best in Figs. 5 and 12- the legs 32 are hollow sheet metal members which form four sides of a hexagon in crosssection, the ends of said sides being wiped over to form a rounded closed surface engaging foot 36-; It will thus be seen that we, provide hollow ljegs, open on, the inside thereof as at 31; which combines lightness 3 of weight with extremely high rigidity. The arms 33 are preferably formed of similar crosssectional contour to the legs 32, the ends of said links being pinched as at 39, where they are attached as by rivets to ears extending from the collar 30. p

The screen casing l2 and its supporting bracket 22 are so disposed on the pedestal 25 with reference to the legs 3! that when the casing I2 is arranged parallel to the pedestal, as for carrying, it will lie between a pair of legs 32. Thus, when set up, the legs may be extended and the reel casing may be moved freely from vertical to horizontal position.

The pedestal 25 comprises: a tube 42 which is preferably rectangular in cross section and a similarly shaped tube 45 telescopically arranged therein. The tube 45 carries adjacent its upper extremity a securing member 45 which also may be formed out of sheet metal and comprises a cap portion 4'1 closing the end of the tube 45 and a double hook portion 48, 48' the lower prong of which engages in a cavity 45 in one of the end caps i5 of the screen housing l2 for securing said housing in position parallel to the pedestal.

A collar 50, seen best in Fig. '7, which has its upper edges 5i rolled over to form a neat juncture between the tubes 42 and 45, retains a resilient plate or spring 53 the upper edge of which is bent as at 54, so as to be easily retained between the upper edge of the tube 42 and the underside of ledge 5| of the collar 50. The spring 53 is bowed as at 56 so as to press resiliently against the inner tube 45, as seen best in Fig. 9.

A stirrup-like resilient clip 55 embraces the collar 58, said clip having a pin 5'6 which extends through registered apertures 5'! and 55 in the outer tube 42 and in the collar 50, respectively. This pin, 56, looks the collar or cap 59 in place and by cooperating with apertures 55 disposed at intervals along the front face fill of the inner tube 45, also serves to lock said tube at any desired height, while the spring 53 urges the inner tube forwardly, keeping it in locked relation with the pin 56. i

The outer tube 42 (see Figs. 2, 3, 4 and 6) is provided with a longitudinal slot 55, which terminates at the top in a transverse slot 65. The

bracket 22 is also provided with a slot 53. A key K passing through the bracket 22 and the outer tube 42 serves to lock the screen housing and the stand in assembled relation. As seen best in Fig. 6, the key K is notched as at 59 to receive the edges of the slot 55 and ride therein. This key is also notched as at '50 to enable it to be easily grasped by the finger nails and preferably has a U-shaped cut out at its forward end, as at H. Thus, the major weight of the dog is toward the rear thereof, a feature which facilitates its assembly. The key or dog K limits the downward movement of the case by resting at the lower end of slot 55. This assures the center or pivotal position of the case. The extension or slidable tube 45 carries the stirrup 12 quite a distance below the keyand disengaged therefrom. The stirrup engages the key on upward movement after the tube 45 has been freely raised to extend the screen fabric to its full open position. Then the stirrup '12 engages key K and any further upward movement of tube 45 will carry the key and case upwardly therewith. This construction makes possible the automatic raising and lowering of the case during the adjusting movements of thetube 45. The inner tube 45 carries at its lower extremity a stirrup-like member 72 (Fig. 23 secured as by a rivet I3, said stirrup extending forwardly as at 14 to underlie T-shaped portion 75 of key K. This portion is narrower than the body of the key, so that it will pass through slot as while the body part will be stopped from entering the slot.

Assembly of the screen housin with the stand is simple and convenient. The bracket 22, carrying the screen housing, is passed over the outer tube 42 and arranged with its slot 58 in registry with slot 65 of the outer tube 42. The key K is then inserted through both slots until it reaches the position shown in Fig. 2, for example. It should be understood that when this assembly is accomplished the inner tube 45 may be at any osition relative to the outer tube, provided stirrup 22 is below slot 66, but the inner tube is preferably fully retracted. The stirrup is inoperative in this position. In any event, the key K with the bracket and screen case will be passed down through the longitudinal slot 65 until the key comes to a position of rest at the bottom of slot 55. The cap is then arranged on the end of tube 42 with spring 53 in place and locked with the spring clamp 55. This completes the assembly.

Further operation of the device will be obvious. When the screen is set up, the folding legs 3% are, of course, extended and the hook 48 disengaged from the screen casing and tube 42 raised to a desired height. The screen housing is then rotated from its position parallel to the stand to its horizontal position. The screen is then raised by means of its loop 15, and the latter is secured over the hook 48'. If desired to give the screen further elevation after the inner tube has been raised until stirrup 12 engages key K, then tube 45 may be further extended nearly the full length of slot 55 or until the stirrup ."2 meets the lower end of spring 53, carrying the screen housing with it bodily, by means of the interlock of stirrup l2 and key K. The tube 45 may be fixed at any point along its length by means of apertures 59, engaging stud 55. Said apertures may be placed'as close together as desired. Demounting may be accomplished by the reversal of these stepsjust described.

The key K is capable of slight rocking movement, whereby it dips downwardly bitinginto the adjacent tube when the screen is raised, by reason of the tension exerted by the casing. Thus, the case is locked against any tendency to ride upwardly on the tube. Thus, it will be seen that this key K performs several important-functions.

It will be seen that we have provided a portable screen and stand which is extremely compact, formed of a minimum number of simple parts and is extremely light, while at the same time rugged and highly serviceable.

While we have disclosed the inner telescopic member as a tube for preference, because of light weight and economy of metal, it could obviously be a solid rod of light metal, plastic, etc.

Various other changes coming within the spirit of our invention may suggest themselves. Hence, we do not wish to be limited to the specific forms shown, but claim a full range of equivalents.

We claim:

1. A combination screen and stand comprising a screen reel and housing therefor, a stand comprising inner and outer telescopic members, a bracket carrying the screen housing slidably 1 mounted on the outer telescopic member, andim terlocking means retaining the bracket on the stand, a member on the inner telescopic member engaging with said interlocking means after said inner telescopic member has been partially raised, after which said bracket and housing may be elevated as a unit with said inner telescopicmemher.

2. A device as defined in claim 1, wherein the interlocking member is removable and extends through the bracket and outer telescopic memher, the latter being longitudinally slotted to provide a passage for movement of said interlocking member therealong and said slot being enlarged at one portion thereof to facilitate removal or insertion of said interlocking memher.

3. A combination as described in claim 1, wherein said interlocking means comprises a key member removably disposed between the bracket and the outer telescopic member, said bracket and outer telescopic member being slotted to receive said key and the latter being tiltable in said slots to produce a clamping effect against the outer telescopic member as a result of tension produced by raising the screen, thus preventing undesirable following of the housing when the screen is raised.

4. A device as defined in claim 1 wherein the outer telescopic member has an axially elongated slot in which said interlocking member rides when the stand is extended and collapsed, said slot having an enlarged transverse portion for insertion and removal of said interlocking member when assembling and demounting the device, said inner telescopic member having means carried at the lower portion thereof engageable 6 with said interlocking means when said inner telescopic member has been raised substantially its full length whereby further raising of said inner telescopic member will also lift the screen housing.

5. A device as defined in claim 1 wherein the outer telescopic member has an axially elongated slot and the interlocking means comprises a relatively fiat plate having a pair of opposed lateral notches serving as trackways for the side walls of said slot, said plate for its major extent being substantially wider than said slot.

6. A combination as defined in claim 5 wherein said notches are substantially wider than the thickness of metal of the walls of said slot whereby the interlocking means is capable of limited rocking movement relative to the walls of the slot.

LEO J. DU MAIS.

JOHN T. I-IECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,902,373 Pineo Mar. 21, 1933 1,915,944 Nagel June 27, 1933 1,917,369 Heck July 11, 1933 2,273,791 Wirgin Feb. 17, 1942 2,298,380 Hood Oct. 13, 1942 2,370,235 Du Mais Feb. 27, 1945 2,377,553 Heck et al. June 5, 1945 2,384,710 'Irippensee Sept. 11, 1945

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