US2864577A

US2864577A - Foldable standard base structure

Info

Publication number: US2864577A
Application number: US453289A
Authority: US
Inventors: Mais Leo J Du
Original assignee: DA LITE SCREEN CO Inc
Current assignee: DA LITE SCREEN CO Inc
Priority date: 1954-08-31
Filing date: 1954-08-31
Publication date: 1958-12-16
Anticipated expiration: 1975-12-16

Description

Dec. 16, 1958 L. J, DU MAlS FOLDABLE STANDARD BASE STRUCTURE Filed Aug. 51, 1954 FIG. 2

H l Jr J' 3l I l 4 T JH 5 INVENTOR: a" LEO J. Du MAIS B Y MAJ ATT'YS United States Patent f) FOLDABLE STANDARD BASE STRUCTURE Leo J. Du Mais, Chicago, 111., assignor to Da-Lite Screen Company, Inc, Chicago, Ill., a corporation of Illinois ApplicationAugust 31, 1954, Serial-No. 453,289

3 Claims; (Cl. 248171) This invention relates to screen stands and analogous structures of the kind which comprises an upright standard and a supporting base structure, comprising a plurality of legs of tripod or other foldable'form, which legs are hinged to the'standard in "such manner as to be setting up and taking down the standard; and 'to provide improved latching'means for-the tripod legsthat operates in an improved fashion to hold the legs 'intheir collapsed position for storage and that is readily unlatched by manipulation of the standard withone of the legs in contact with the floor and wherein, upon such unlatching the legs by downward pressure and tilting of-the standard, the legs will be. automatically spread apart by spring recoil and gravity upon being lifted from the floor.

An illustrative specific embodiment ofthis invention is-shown in the accompanying drawings,-in which:

Figure 1 shows the standard with its-legs in collapsed positioniand tilted to an initial position for causingthe legs to spread apart.

Fig. 2 is a perspective view of thestandard with. its legs'spread apart for supporting the standard upri-ghtyon a horizontal floor.

Fig. 3 is a longitudinal section of the standard with its legs latched in collapsed position and showing the structure of the leg mounting brackets and latch mechamsm.

Fig. 4 is a transverse section of the same taken on the line 4-4 of Fig. 3.

Fig. 5 is a transverse section of the tubular standard taken on the line 55 of Fig. 3.

In the form shown, the standard is a tubular bar equipped with tripod legs 11 which are foldable to a collapsed position, as illustrated in Fig. 1, for compact storage when it is out of use. It is adapted to have its legs spread apart for supporting the standard 10 in an upright position.

The standard 10, as illustrated in the drawings is preferably of rectangular cross section and has .an upper bracket member 12 that is longitudinally slidable on the standard 10, a lower bracket member 13 which is also longitudinally slidable on the standard but to a more limited extent, and an intermediate bracket member 14 which is fixed to the standard. Each of the bracket members has wing-like lugs directed radially outward from the axis of the standard and each lying within the plane of movement of a respective leg when such leg is shifted between its expanded and collapsed positions.

The upper ends of the legs 11 are pivoted at 15 to the lugs 16 of the upper bracket member. Spreader links 17 are pivotally connected at 18 to the lugs 19 of the lower bracket and their outeror upper ends are pivoted by pins 20 on the leg 11 in position to engage latch hooks on the intermediate bracket member 14.

As. shown in Figs. 2 and 3,

thebracket members

12 and 13 are of identical form, but one is inverted with.

respect to the other in their positions on the.standard.

The intermediate bracket member 14 is similar in structural make-up except that, instead of having merely circular bores in its winglugsfor the reception of pivot pins, it has a slot 22.inclined downwardly and inwardly from the outer end of the lug so that the inner end 'of' theslot 22 will serve as a seatfor thepivot pin 20 and; its sides .will serve as

cam surfaces

24 and 25 "adapted to guide the pin 20 into and out of such seat. The lower portion of each wing lug of bracket 14 'formsa latch hook 23 that partlyembraces such pivot pin 20. The pivot pin 20, in addition to connecting the spreader link to its leg, has the extra function of serving as a.

keeper coacting with the latch hook 23 to hold the respective' leg in. its collapsed position, as clearly shown in' Fig." 3. The .bracket '14 is fixed on the standard 10}.

as .by a set screw 26or otherwise as may be desirable to conform to localconditions 0n the standard.

For convenience of manufacture, the legs 11 are of inverted channel-form in section .and the spreaderbars,

17 are'also of channel form so that these barsnest one within another, as. shownat the left of Fig; 3, when the respective leg is in its collapsed position.

alongtheytube 10, which movement is limited bythe ends of slots.28.i

A'compression spring 29.bears betweenthe cross pin. 27 "of' the bracket member. 13"and a cross pin 30 within.

the tube 10,"so' that this. spring 29"'normallytends to.urge

the bracket member 13' downwardly along the tube.10

and acting through. the linkl17,normally holds the keeper and pivot pin 20"in-position for latching engagement; with the hook 23 to hold .the legsin their retracted 0rcollapsed position along the tube 10," as shown in Fi'g BT.

v The three bracketmembers are of identical "construction exceptfor the fact that the slots 22 in the wing lugs of the bracket member 14 are modified by having the slot 22 extend from the pivot bore outward to the end of the lug, as hereinbefore described. Preferably, these bracket members are each made up of three straps that form segments of a band around the standard 10 with wing portions projecting from this band to form the wing lugs which serve as hinge members. The hole 27.1 of bracket 12 may serve to permit the attachment of a fingerhold (not shown) to be attached to bracket 12 if desired.

In the operation of spreading the legs to set up the standard, the operator holds the tube 10 in an inclined position with one of its legs bearing on the floor in about the disposition shown in Fig. 1. The legs are equipped with rubber cups 31 which will not mar a smooth surface or tear a carpet. While only one of the legs is in contact with the floor, as shown, the operator presses the standard downward and rocks it away from the point of contact with the floor as indicated by arrow 32, compressing the spring 29 of that leg against the cross pin 27. The latch hooks 23, being fast on the standard 10, thus move downward with respect to the keepers 20 on the legs 11, whereupon cam surfaces 25 of the slot 22, coacting with the keeper pins 20, cause the legs to spread apart and free the keepers 20 from the hooks 23.

After the legs have spread apart sufiiciently to free 3 the keepers 20 from the latch hooks 23, the bracket member 12, due to its weight and that of the parts connected thereto, falls by gravity until it is stopped by the bracket-member 14 with the legs fully spread apart, as shown'imFig. 2, and thedevice is ready to be set up right on the floor.

.To collapsethe legs, it is merely necessary for the operator to slide the bracket member 12 upward along the tube to cause the links 17 to swing inward until the keepers 20 ride up on the cam surfaces 24 and snap over the hooks 23 into their latching position, due to the normal urge of the spring 29.

, Although but one specific embodiment of this invention is herein shown and described, it will be understood that numerous details of the constructionllshown may be altered or omitted without departing from the spirit of,the invention as defined by the following claims.

I claim: a

1. In a stand of the class described, a standard, an upper bracket member slidable along said standard, supporting legs for the standard pivoted on said upper bracket member to swing in radial planes between spread apart and collapsed positions, a lower bracket memberslidable on said standard, coacting means on the standard and lower bracket for limiting the move ment of the bracket on the standard, spreader links pivoted at their lower ends to said lower bracket member and at their upper ends to respective said legs and adapted to swing said legs outward from said standard when said upper bracket member is shifted downward along said standard and to swing said legs inward toward said standard when said upper bracket member is shifted upward along said standard, a rigid intermediate bracket member fixed on said standard having upwardly-opening latch hooks thereon individually extending radially therefrom in the paths of movement of respective legs with respect to the standard, keeper means on said legs intermediate their ends adapted to be engaged by said latch hooks when the legs are in their collapsed position, and spring means acting between said standard and said lower bracket member to urge the lower bracket downwardly on the standard to hold said keeper means normally in position for engagement with said latch hooks and adapted to yield through the relative movement of said standard and said lower bracket member to release said keeper means from said latch books.

2. In a standlof the-class described, a standard, an

' 4 upper bracket member slidable along said standard, supporting legs for the standard pivoted on said upper bracket member to swing in radial planes between spread apart and collapsed positions, a lower bracket member slidable on said standard, coacting means on the standard and lower bracket for limiting the movement of the bracket on the standard, spreader links pivoted at their lower ends to said lower bracket memher and at their upper ends to respective said legs and adapted to swing said legs outward from said standard when said upper bracket member is shifted downward along said standard and to swing said legs inward toward said standard when said upper bracket member is shifted upward along said standard, a rigid intermediate bracket member fixed on said standard having upwardly-opening latch hooks thereon individually extending radially therefrom in the paths of movement of respective legs with respect to the standard, keeper means on said legs intermediate their ends adapted to be engaged by said latch hooks when the legs are in their collapsed position, and spring means acting be tween said standard and said lower bracket member to urge the lower bracket downwardly on the standard to hold said keeper means normally in position for engagement with said latch hooks and adapted to yield through relative movement of said standard and said lower bracket member to release said keeper means from said latch hooks, and cam surfaces on said latch hooks coacting with said keeper means to force said legs apart through further relative movement of said standard and lower bracket member.

3. A stand structure according to claim 2 in which the spreader links are pivoted by pins at their lower ends to said lower bracket member and by pivot pins at their upper ends to respective said legs and the keeper means are the same pivot pins that connect the links to the legs.

References Cited in the file of this patent UNITED STATES PATENTS 575,529 Stephens Jan. 19, 1897 1,163,639 Clay Dec. 14, 1915 1,181,007 Henneberg Apr. 25, 1916 2,378,150 Michaud June 12, 1945 2,549,584 Eller Apr. 17, 1951 2,591,244 Du Mais et a1. Apr. 1, 1952