US3166115A - Collapsible stand for a flexible projection screen - Google Patents

Description

H. RIEDEL 3,16%315 COLLAPSIBLE STAND FOR A FLEXIBLE PROJECTION SCREEN Jan. 1%, 1965 Filed May 11, 1961 5 Sheets-Sheet 1 Fig.1

H. RHEDEL 3,166,135

COLLAPSIBLE sumo FOR A FLEXIBLE PROJECTION SCREEN Jam 19, E5

5 Sheets-Sheet 2 Filed May 11. 1961 Fig. 7

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COLLAPSIBLE STAND FOR A FLEXIBLE PROJECTION SCREEN Filed May 11. 1961 I 5 Sheets-Sheet 3 Fig.16..

7 Fig.8 F 63 MV 83 v J64? Qw'A A Jan. 3%, 1965 H. REBEL I J COLLAPSIBLE STAND FOR A FLEXIBLE PRoJEcTIox-z SCREEN Filed May 11. 1951 5 Sheets-Sheet 4 Jan. 19, 1965 H. RIEDEL 3,165,115

COLLAPSIBLE STAND FOR A FLEXIBLE PROJECTION SCREEN Filed law 11. 1961 5 Sheets-Sheet 5 //(//Y///\////)&///////////// United States Patent 3,166,115 COLLAPSELE STAND FOR A FLEXIBLE PROTECTION SCREEN Herbert Riedel, Spitalmuhlenstrasse 13,

SchWahisch-Hali, Germany Filed May 11, 1961, Ser. No. 109,472 Giaims priority, application Germany May 14, 196i 9Ciain1s. (Cl. 166-44) operative condition, can be stretched to the desired eX-' tent. A further advance of this novel construction resides in the fact thata holding bar formingthe main portion of the stand, mounted upon a preferably detachable base and carrying the members that hold the projection screen,

is made hollow so that it accommodates the projection screen in its interior.

The main feature of the stand according to the invention is a preferably vertically arranged holding bar, mounted upon a detachable or collapsible base, there being mountedupon this holding bar two pairs of rocking arms which are designed for holding the two battens that keep the projection screen taut between them. At least one pair of these rocking arms are secured to a ring slidable along the holding bar for the purpose of adjusting the desired tension of the projection screen. The slidable ring is in connection, by Way of a screw-threaded bolt provided with a knurled disc, with a fixed ring 'provided on the holding bar; The upper pair of rocking arms are in particular linked to the upper holding ring that carriesit in such a way that the rocking arms are rockable upwards out of their inoperative or transport position, in which they bear against the holding bar, through about 120 to 150? towards the holding bar into the operative position, where they come into contact with abutments provided on this upper holding ring. The lower rocking arms are so linked to the lower holding ring that carries them that they are rockable upwards towards the holding bar through about 30 to 60 out of the transport position, in which they likewise bear against the holding bar, into the operative position, where they come into contact jwithjabutments provided on this lower holding ring. I V

The holding bar, as mentioned, is preferably made hollow, 'andconsists in particular of a plurality of telescopically movable tubular sections, preferably two, which can be fixed relatively to one another inthe drawn-out The outer tube of the telescopic holding bar, or the "ice dition in such a way that three such foot members, for example, are spaced apart by angles of 120.

The above and other objects, features and advantages of the present invention will become more readily rings holding the pairs of rocking arms, preferably .the

lower holding ring, may advantageously be soconstructed that the par-ts of the detachable foot of the stand, in the transport condition, can be secured parallel to the holding bar, on itsouter walls; In this case the lower holding ring is provided with slots which are arranged around its axis, and which correspond in number and form to the slidable foot members engaging, in the operative position, in a base on the inner holding tube. These slots in the lower holding ring, and also the foot members that are slidable-into them in the transport condition, are slightly curved. The same curvature is exhibited by further slots, which are provided in a base on the lower (inner) .tube member of the holding bar, and into which the foot members can be inserted for the operative conapparent from the following description, reference being made to the accompanying drawing wherein: FIG. 1 is a fragmentary front-elevational view of the stand for a projection screen according to the present invention;

FIG. 2 is a side-elevational view of the stand; FIG. 3 is a transverse cross-sectional view showing the base of the stand in planview;

FIG. 4 is a detail view of the central portion of the stand; i

FIG. 5, is a detail view of the tightening and detent means;

the stand; FIG. 7 is a front-elevational View of the upper carrie FIG. 6 is a plan view of the lower carrier member of,

member according to another embodiment of theinvention;

FIG. 8 is a side-elevational view, parts broken away, of the post of a stand according to still another embodiment of the invention;

FIG. 9 is a front-elevational view of the stand of FIG. 8;

FIG. 10 is a plan view of the upper carrier member of the stand;

FIG. 11 is a plan view of the lower carrier member 7 thereof;

FIG. 12 is a front-elevational view of the upper carrier member showing the detent means for securing its arms in their operative position;

FIG. 13 is an elevationalvview of one of' the arms" showing the detent means in greater detail;

FIG. 14 is a longitudinal cross-sectional view through the arm of FIG. 13; FIGS. 15 and 16 are cross-sectional views illustrating the catch means of the arms of still another stand ac-,

the operative position, the transport position of the-rock-' ing arms being at the same time indicated in broken lines.

The main portion of the stand is formed by a tubular.

post 1, extending vertically, the lower portion of which opens into" a base, on which the foot members 27 are. mounted. At the upper portion of this tube 1 is arranged. an upper holding ring 2, which is axially slidable' on the stand tube and is so connected, by way of a screw threaded bolt 4 having a knurled'disc 3, with a fixed-ring 5 likewise provided on the stand tube that the distance between the rings 2 and 5 can be adjusted at thefusei s, choice. On the movable ring 2 are mounted an" upper' pair of rocking arms 6 and 7. The ends of these rocking arms are capable of being connected with an upper batten 34, to which is secured one edge of the flexible projection screen, which is preferably capable of being rolled up. This projection screen is marked 17 in FIGS;

1 and 2. p

'As can be seen more particularly from FIG. 1, abutment surfaces 8 and 9are provided on the upper holding. ring 2. for the rocking arms 6 and 7; these abutment surfaces fix the operative position of the rocking arms when they are swung upwards about suitable pivots out of their position 6, 7', shown in broken'lines, in which they lie against the outer tube 1 of the stand. In orderfthat extending feet thereof and 4).

bers 27, which are made slightly curved to correspond to tion under the action of gravity, there are provided, on

the holding ring2, two pins and 11 which can be resiliently pushed in, and which can be depressed by the user against a spring in the interior of the. upper holding ring 2, as shown more particularly'in FIG. 5, the rocking arms 6' and 7 slipping over the ends of the pins 10 and 11 until'they clear the pins upon striking against provided: The lower holding ring 24, which holdsthe rocking arms 25, 26 and encircles the outer tube rn'em-' the surfaces 8 and 9, whereupon these pins, being pressed outwardly again by their springs, securethe arms 6 and 7'i'n the operative position.- e

Further towards the middle of the tube 1 of the-stand is provided a lower holding ring 24, which carries a lower pair. or rocking arms 25, 26', constructed like the. 2

"arms25 and 26 are connectable with a second batten 37,

which holds the loweredge of th'e projection screen 17,

For transport purposes the tube 1 can accommodate in its'iritei'iof the rolled-up projection screen 17, with its battens '34- and 37.' For this purpose the upper end of the tube 1 is provided with a resilient'cover 29, which has on its periphery three resilient holding lugs 19 hearing on the external surface ofthe upper tube 1 of the stand; the lower ends of these lugs are slightly bent round towards the axis of the tube, so that in the corresponding osition ofthe cover they can-engage in holding slots 13..

The lower bent edgescf these holding lugs-19, or the edges of the holding slots 18, may 'advantageously be beveled in such a way that for the removalof the cover 20 mounted thereon only a slight rotation is necessary,

ber 21 of the post 1 is recessed in a radial direction so as to present three slots 44 which conform to the slots 31 of the base 29. Into these slots 44 the foot members 27 taken out of the base 29 can be inserted in such a way that they bear against the external wall surface of the outer tube 21, as shown'more particularly in FIG. 2, where these foot members, removed for transport, are designated with the numeral 27. Owing to their own curvature they bear snugly upon the convex surface of the tube 22. In. order that the ends of the foot members 27 directed in this position towards the upper holding. ring 2 maybe secured in their position during which the" bent ends of the holding lugs 19 slipout of the slots 18, so that thecover can then be removed in an upward direction without hindrance. p V

The post 1 consists of two telescopically movable tubu- 151" members, an outer tube 21 and an inner tube 22;

These two tubular members are connected with one ofpswing, and which fits into a corresponding bore or: recess inthe neighborhood of the ends of the battens another bya knurled nut23, by the rotation of which, via'aco'riica l screw thread, the connection between the two tubes can'be established or released.

For 'applying'o'i removing a foot carrying the tubular post Lthere provided on the tube member 22 a base 29, which is provided with holding slots 31 (FIGS. 3

Into the latter can be inserted three foot memthe curvature ofthe slots 31. In order to fix the foot members 27 in the'op erative condition in the slots 31, the insertableends of the foot members are each provided with one or more longitudinal slots 32 (FIG..3), which result in a slight resilience of the outer foot-rnember ends formed thereby, thus enabling latching. means 33 to be applied. The latter. consist of lugs provided on the lateral edges of the slots, in which the 're fit cor-responding cheeksgon the resilient flanks of the foot members 27.

jEa/chbf thel foot members 27 is provided on its upper side with] one or more stifiening ribs 40 (FIG.'1), which, at their ends bearing on the base 29, are connected with one another by bridge'piecfes4l (FIG. 3), the surfaces of which have the same curvature as the external surface of the base. By these bridgepieces 41 the foot members 27 are additionally braced against the base 29, owing tothe 'fact that a sliding ring 42 which surrounds the base,

and'which is providedto lugs 43 corresponding with the number of foot members, can slide into an operative position with these lugs interposed between the stifiening ribs, so that the lugs '43 overlie in front of the bridgepieces 41.

In order that the foot members 27 may require 'as' little space as possible to accommodate them in the transport position ofthe stand, the following means are for transport, a clamping ring 30 ('FIG. 2) surrounding the tube 22 is provided. Ring 30 has resilient lugs 46' which bear upon the tube 22 in such a'wayfthat, after theclamping ring 30 has been slipped over theends'of the; foot members 27,'no further change of position can ocour. The slots 44 of-the holding ring 24 are moreover located, as is likewise. shown in FIG. 6, on the side. remote from the flattened portion of this; holding ring,1 this flattened: portion containing the fastening means for the rocking arms 25 and 26. Hence," in the transport position, the rocking arms 6 and 7 bearing against the tube 21, on the one han'd,'and the inserted foot members 27, on the other hand, do notget in one anothers way. This is alsoto be gathered in particular from FIG. 2, which, as compared with FIG., 1, represents a rotation about the post 1 through 180.

For holding the battens 34 and 37, which carry the flexible projection screen 17 by two opposite edges when it is stretched out in the operative condition, the fol-.

lowing meansare provided on the pairs of rocking arms 6,7 and 25, 26, shownparticularly' in FIGS. 1, 2 and 5. Each rocking-arm carries, in the neighborhood of its outer end, a .pin'47, which. is perpendicular to its plane 34 or 37. In the vicinity of this pin 47 there is also provided on the rocking arm a rivet or the. like 48, around which a generally 'J shaped clamping shackle 49 is rotatable'whose bentover end yieldingly embraces the batten 34 or 37 in the operative conditionflthereby se curing it against slipping out of the pin 47. The clamping shackles 49 may be either hired to the rivetor, as

shown 'in- FIG. 1, may be so constructed that. they 5 can be yieldinglyslidinto a slot in the latter, andican be correspondingly released.

When the projection screen 17 is stretched between v the battens 34 and 37 in the'manner described, the tension is in case of need increased to-the' desired degreeby turning the knurled disc 3 (FIGS.-2 and 5) in the sense of an upward movement of the upper holding ring 2 away from the fixed ring 5.. In the transport con dition the clamping shackle 49 is turned through about 90 away from'the projection surface (see the dotted position 49'. in FIG. 1), so that the battens 34 Ja nd37 I can be removed and can be stored (after therblling' up of the projection screen 17), as indicated, in the interior;

FIG. 7 shows a simplified construction of theppper holding ring 2 for-the rocking arms 6 and 7, wherein the spring-controlledabutment pin10 or,.11'of FIG. 5 can be dispensed'with. 'The securing of these rockingarms 6 and 7 in the operative position here efiected by means of a two-armed shackle 50, rotatably supported at the pivot point 51, whose downwardly bent ends 52 land 53 of which are curvedat their ,outer' edges abouttapproxi- I mately the thickness of the rocking arms 6 and -7, so that' V the shackles engage under these arms in the operative;

position and supportthem "against dropping out. ,For. the transport position, the slightly resilient shackle ends i 52 and 53 are disengaged from the associated rockingarms, and the shackle '50 is brought preferably into" the position 50' shown in broken lines in FIG. 7. The 'r'ocking arms can then resume their positions shown in broken lines in FIG. 1, parallel to the tube 1.

Another embodiment is illustrated in FIGS. 8 to 14. This embodiment is distinguished from the first one by the fact that in the upper part of the tubular post 84 a telescopic tubular element 57 with an external screw thread 82 is slid over that post down to an abutment 81. This tubular element furthermore rests with an inwardly directed annular projection 83 upon the upper end of the tube 84. Owing to this, the tubular element 57 cannot slip down the post 84 during the tensioning operation of the screen. The annular projection 83 also serves for relieving any load on the collar 81.

The upper rocking-arm ring 55, with its internal screw thread 56 (FIG. 10), is screwed over the tubular element 57, the element 57 being rotated by means of a knurled projection 91. In order that the ring 55 may not turn with it, there is inserted from below, in a curved slot 88 in a segmental extension 87 of this ring, a correspondingly curved tongue 89, which is firmly clamped therein. The lower end of the tongue, slipping easily, engages ina slot 103 in a guiding ring 90, firmly secured to the post 84. The telescopic tubular element 57 is closed at the upper end by a cover 85, secured by means of a screw thread 86. V

The upper rocking-arm ring 55 is provided, on the side opposite the segmental projection 87, with a double rocking-arm bearing 58, which comprises a front cover plate 69 and a rear cover plate 66 separated by a slot 59 into which the ends of the upper rocking arms are inserted, one from each side, and in which they are rotatably supported by bolts 67.

The rocking arms 68 are of shallow channel-shaped cross section, and are supplemented, in the neighborhood of the rocking bore 75 at one end, with a cover sheet 77 (FIG. 14) to form a box-like cross-section. In the vicinity of the rocking bore 75 an anti-friction roller 69 is journaled within slots 73. Through a central bore in the rocking arm there passes a guiding pin 71, which is supported within the rocking arm. A compression spring 72 coiled around the guiding pin tends to push the roller 69 towards the left-hand end of the slot 73. The roller 69 is guided by glide-discs 74 along the walls of the rocking arm and of the cover sheet 77. At one end of the roller an actuating knob 78 is provided, and at the other end there is an abutment disc 79.

The front and rear cover plates 60 and 66 are provided with cam guides 78 (FIG. 12) extending in an upward and outward direction from below and terminating at the top in a notch 63.

Upon the rocking arms being rocked out of the downwardly directed transport position illustrated in FIG. 12 for the right-hand rocking arm, the associated roller 69 glides upwards along the cam guides 78 while it moves within the slot 73 towards the outer end of the rocking arm, overcoming the thrust of the compression spring 72, until the detent roller snaps into the notch 63. In this position the upper edge of the associated rocking arm 68 abuts against an inclined surface 64 in the slot 59.

The lower rocking-arm ring 92 carries the lower rocking arms 95 rockably about pivots 94 on a rocking-arm bearing 93.

As the lower rocking arms rock upwards, they penetrate, in the vicinity of the rocking pivots, into slots 96, which are provided in guiding blocks 97 on the two outer sides of the rocking-arm bearing 93, until they come into contact with the base 98 of these slots 96. The rocking arms 95 are thereby secured against tilting, and at the same time the pivots 94 are relieved. v

The lower rocking arms are likewise channel-shaped and shallow, but are so much narrower in breadth than the rocking arms 68 that, when both pairs of rocking arms are folded down, the lower portions of the-upper rocking arms 68 embrace the lower rocking arms 95, as shown in FIG. 11. A particularly compact formation port' position is thereby attained.

The two pairs of rocking arms are held in the transport position by means of ,a resilient lockingband 99 wound around them and attached to a latch 100. i

The mounting and demounting and the construction of the feet 101 of the stand shown in FIGS. 8-14 are the same as in the firstembodiment. The feet of the stand 1n the transare also hold in the same manner, between the lower rocking-arm ring 92 and the clamping-ring 102, for the trans port position. The only difference is that in the present embodiment the clamping ring 102 is arranged underneath the lower rocking-arm ring, whereas in the first embodi ment the clamping ring is supported above the lower rocking-arm ring.

In the embodiment illustrated in FIGS. 15 and- 16, at the ends 104, 109 of the rocking bars 6, 7 or 25, 26 instead of the pins 47, as shown in the embodiment illus-' trated in FIGURES 1 and 2, generally rectangular shackles 106, 111, rotatable about rivets 105, 110, are

provided. On the sides of the shackles orthoganol to the rocking bars these shackles have pins 107, 112, each of" which is connected with a corresponding bore or recess in the battens 108, 113 of the flexible projection screen, thus serving for the bearing and stretching of the flexible projection screen. 7

In accordance with the construction shown in FIGS. 17 and 18, in departure from the showing in FIG. 1 the base 29 shownthere is replaced by base 115 of a rectangular shape which is pushed from below over the lower tube member 114 by means of its socket 121 and fixed thereto. The base 115 carries in bearing holes 122 bolts 116 which are flattened in the respective ends 117 protruding from the base and are'provided with a transverse bore 118 through which a pivot 119 extends for the pivotal mounting of the respective feet 120.

In the position of use each foot 120 rests with an upper lug 121 against the base 115 so that the stand rests on the floor at the ends 123 of the four feet only. For transport purposes each foot is rotated around its longitudinal axis whereby the second pivot means 116 in the bearing hole 122 is rotated until the lug 121 extends vertically downwardly. Then the foot member 120' can be tilted around the pins 119 forming the first pivot means towards the" carrier member for swinging displacement substantially in a plane parallelto said post outwardly into an operative position, wherein said first arms diverge upwardly beyondsaid post, from an inoperative position wherein said first arms extend substantially codirectionally with said post; a pair of rigid second arms pivotally connected with said lower carrier member for swingingdisplacement substantially in said plane'outwardly into a down- 1 wardly diverging operative position from an in-operative position wherein said second arms extend substantially.

codirectionally with said post; a projection on thefree end of said first and second arms engageable with an upper and a lower batten, respectively, of a projection screen; latch means at each of said free ends for releasably maintaining the battens so engaged in positively connected relationship with said arms; holding means on each of said members for retaining the respective arms in their operative positions, at least one of said members being longitudinally shiftable on said post; and tightening means on said post operatively connected with said one of said members for relatively displacing said members longitudinally away from each other, thereby tensioning i, a the projection screen spanning said battens in the operative positions of said arms.

2. The combination according to claim 1 wherein the holding means of each of :said members includes respec tive fixed abutments engageable with the respective arms 5 in the operative positionsthereof. a 3. The combination according to claim 1 wherein said base is provided with a central portion, a plurality of feet, first pivot means connecting :said feet with said central, portion forlswinging movement about axes trans-z 1 verse. to said feet fromoperative positions wherein said feet extend generally radiallylto inoperative positions wherein said feet extend generally in a common direction and second, pivot means having respective radial axes interconnecting each, of said feet. with-said central 'portion whereby said feet can be swung about their respective'radial axes to lock them in their operative positions.

4. The combination according to claim 1 wherein said latchj means on the free, end of each of said arms comprises a generally Jeshaped shackle positionable to em brace the respective batten.

5. The combination according to, claim 1 wherein the arms of at least one of said pairs are channeled to rec ive the arms of the other of said pairs in theinoperative positions of said arms, said arms of said one, of said said inoperative positions, V s

6. lThe'combination according to claim; 1 wherein said pairs overlyingthe arms of said other of said pairs in post is tubular and'adapted to receive'saidscreen in a rolled-up condition thereof, further comprising, rem0v-' 3O able cover means attthe upper end of said post for closing the interior thereof. a

7. The combination according to claim*6 wherein said post comprises a pair of telescopable sections, eachof said members being mounted upon a respective one of said sections. 4 I V 8. In a collapsible stand for a projection screen, in combination, a base; an upright post mounted on said. base; anupper and a lower carriermember axially spaced along said post; a pair of first arms pivotally connected with said upper carrier member for swinging displacement substantially in a plane parallel to said post outwardly into an operative position wherein said first arms' are detachably engageable with an upper batten of a projection screen .at locations spaced on opposite sides direc'tionally withsaid post; holding means on 'each of said members for retaining the-respective arms in their operative positions, at least one of said members being longitudinally shiftable on said post; tightening means on said post operatively connected with said one of said members for relatively displacing said members longitu dinally away from each other, thereby tensioning a screen spanning said battens in the operative positions of said arms, said base'being provided with a central portion and a plurality of angularlyspaced radially extending feet removably secured to said central portion; and retaining means on said post for holding said feet thereagainst upon their removalfrom said central portion,- one of said mem:

bers being provided with a plurality of angularly spaced recesses, said feet each being provided with a first extremity receivable in a respective one of said recesses, said retaining means including a ring independent of said one of said members and longitudinallyv shiftable on said post into engagement with other extremities of said feet for holding sameagainst said post.

- 9. The combination according to claim 8 wherein said first extremities of said feet are each formed with resilient portions yieldably engageable with complementary formations provided in said central portion of said base.

9 References Cited in the file of this patent UNITED STATES PATENTS 572,547

Jungels- Dec. 8, 1896 1,468,369 Moltrup Sept. 18, 1923 1,852,925 Gomery Apr. 5,, 1932. 2,042,443 Buckstone May 26, 1936 2,346,274 Raven Apr. 11, 1944" 2,534,552 Heck et al. Dec. 19, 1950 2,780,282 Cox Feb. 5,, 1957 2,855,169 Hintz Oct. 7, 1958

Claims (1)

1. IN A COLLAPSIBLE STAND FOR A PROJECTION SCREEN, IN COMBINATION, A BASE; AN UPRIGHT POST MOUNTED ON SAID BASE; AN UPPER AND A LOWER CARRIER MEMBER SECURED TO SAID POST AT AN UPPER LOCATION CLOSE TO ITS TOP AND AT A LOWER LOCATION REMOTE FROM SAID TOP, RESPECTIVELY; A PAIR OF RIGID FIRST ARMS, PIVOTALLY CONNECTED WITH SAID UPPER CARRIER MEMBER FOR SWINGING DISPLACEMENT SUBSTANTIALLY IN A PLANE PARALLEL TO SAID POST OUTWARDLY INTO AN OPERATIVE POSITION, WHEREIN SAID FIRST ARMS DIVERGE UPWARDLY BEYOND SAID POST, FROM AN INOPERATIVE POSITION WHEREIN SAID FIRST ARMS EXTEND SUBSTANTIALLY CODIRECTIONALLY WITH SAID POST; A PAIR OF RIGID SECOND ARMS PIVOTALLY CONNECTED WITH SAID LOWER CARRIER MEMBER FOR SWINGING DISPLACEMENT SUBSTANTIALLY IN SAID PLANE OUTWARDLY INTO A DOWNWARDLY DIVERGING OPERATIVE POSITION FROM AN IN-OPERATIVE POSITION WHEREBY SAID SECOND ARMS EXTEND SUBSTANTIALLY CODIRECTIONALLY WITH SAID POST; A PROJECTION ON THE FREE END OF SAID FIRST AND SECOND ARMS ENGAGEABLE WITH AN UPPER AND A LOWER BATTEN, RESPECTIVELY OF A PROJECTION SCREEN; LATCH MEANS TO EACH OF SAID FREE ENDS FOR RELEASABLY MAINTAINING THE BATTENS SO ENGAGED IN POSITIVELY CONNECTED RELATIONSHIP WITH SAID ARMS; HOLDING MEANS ON EACH OF SAID MEMBERS FOR RETAINING THE RESPECTIVE ARMS IN THEIR OPERATIVE POSITIONS, AT LEAST ONE OF SAID MEMBERS BEING LONGITUDINALLY SHIFTABLE ON SAID POST; AND TIGHTENING MEANS ON SAID POST OPERATIVELY CONNECTED WITH SAID ONE OF SAID MEMBERS FOR RELATIVELY DISPLACING SAID MEMBERS LONGITUDINALLY AWAY FROM EACH OTHER, THEREBY TENSIONING THE PROJECTION SCREEN SPANNING SAID BATTENS IN THE OPERATIVE POSITIONS OF SAID ARMS.

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