US3670797A

US3670797A - Folding closure construction

Info

Publication number: US3670797A
Application number: US49785A
Authority: US
Inventors: John H Sassano
Original assignee: WEATHER CONTROL SHUTTERS Inc
Current assignee: WEATHER CONTROL SHUTTERS Inc
Priority date: 1970-06-25
Filing date: 1970-06-25
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

This disclosure concerns an accordian fold closure panel of the type pendantly supported on elevated trackway structure and the type adapted for embodiment in a folding door or window closure or in a pendant folding curtain wall closure. Each hinge joint connection joining adjacent slat elements of the folding closure includes mating pintle and groove portions formed respectively on confronting edge margins of each adjacent pair of vertical slat elements of tee folding closure. The pintle structure of each slat hinge connection is of slotted tube form defining a hollow core axial interior extending coextensive of the pintle structure. The opposite end portions of the hollow axial interior of the pintle structure of each hinge joint connection preferably provide means for fixedly receiving upper and lower oppositely projecting threaded screw elements: an upper hanger screw element is threadedly fixed in the upper interior of the pintle structure of a respective hinge joint connections and pendantly supports the folding closure panel from elevated trolley means; a lower guide screw is threadedly fixed in the lower interior of the slotted tube pintle structure and supports guide bearing means operative in grooveway structure formed in horizontal sill means of the folding closure apparatus.

Description

United States Patent Sassano [54] FOLDING CLOSURE CONSTRUCTION [72] Inventor: John H. Sassano, Hollywood, Fla.

[73] Assignee: Weather Control Shutters, Inc., Broward County, Pa.

[22] Filed: June 25, 1970 [21] App1.No.: 49,785

52 U.S.Cl ..l60/118,l60/l83, 160/199, 160/206, 160/235, 292/128 [51] lnt.Cl ..E06b3/48 [58] Field of Search ..160/1 18, 229, 196, 199, 206,

160/231 R, 235, 84; 292/128, DIG. 46

[56] 1 References Cited UNITED STATES PATENTS 2,351,656 6/1944 Auten ..l60/199 2,350,287 5/1944 Michelman. 3,267,990 8/1966 Harris 2,746,540 5/1956 Dixon, Jr ..160/84H X 2,917,915 12/1959 Rainman.. 1,599,438 9/1926 Shelly 3,447,584 6/1969 Smart... 3,463,530 8/1969 Modes ..292/128 Primary Examiner-David J. Williamowsky Assistant Examiner-Philip C. Kannan Attorney-John Cyril Malloy [57] ABSTRACT This disclosure concerns an accordian fold closure panel of the type pendantly supported on elevated trackway structure and the type adapted for embodiment in a folding door or window closure or in a pendant folding curtain wall closure. Each hinge joint connection joining adjacent slat elements of the folding closure includes mating pintle and groove portions formed respectively on confronting edge margins of each adjacent pair of vertical slat elements of tee folding closure. The pintle structure of each slat hinge connection is of slotted tube form defining a hollow core axial interior extending coextensive of the pintle structure. The opposite end portions of the hollow axial interior of the pintle structure of each hinge joint connection preferably provide means for fixedly receiving upper and lower oppositely projecting threaded screw elements: an upper hanger screw element is threadedly fixed in the upper interior of the pintle structure of a respective hinge joint connections and pendantly supports the folding closure panel from elevated trolley means; a lower guide screw is threadedly fixed in the lower interior of the slotted tube pintle structure and supports guide bearing means operative in grooveway structure formed in horizontal sill means of the folding closure apparatus.

6 Claims, 12 Drawing Figures FOLDING CLOSURE CONSTRUCTION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates toaccordian fold closure panel means generally and particularly relates to hanger means for suspending accordian fold panel means and for guidingly constraining the panel means during opening and closing manipulation.

2. Description of the Prior Art I-Ieretofore, a typical practice in pendantly supporting an accordian fold closure panel included a series of hanger projections each projecting upwardly from the pintle structure of the respective hinge joint connections connecting adjacent vertical slat elements. The pintle structure of prior art design generally is of solid form, and the hanger projections pendantly supporting the closure from overhead trolly means being integrally formed on the upper extension of the respective pintle structure. The manufacturing process informing each hanger projection on the pintle structure of a prior art closure slat element is expensive in time and material and also presents difficulty in installation and maintenance. The typical folding closure also incorporates rather ineffective means for guidingly constraining the lower edge margin of the closure during expanding and contracting folding movement: a series of guide projections are each integrally formed to the lower pintle structure of a hinge joint connection and necessitate expensive manufacture procedure. Moreover, the lower guide projections in prior art closure fabrication restricted the flexibility of application of a folding closure and presented problems in installation and maintenance. The closure lock means of prior art design also are of substantially complicated configuration and present problems in manufacture and use; the complicated design of the typical folding closure lock structure increases the costs of manufacture, marketing and installation of a folding closure assembly.

SUMMARY OF THE INVENTION The instant invention obviates many of the above-mentioned objectionable features of prior art closure structure and presents an improved closure construction reducing substantially the cost of manufacture and installation thereof as compared with prior art closures. The principal movement in the closure construction of the instant invention is brought about substantially in the metal-extruding manufacture of the pintle structure of each pintle and slot hinge connection of the accordian fold panel; the pintle structure is extruded in generally slotted tube form. This permits an upper and a lower screw element to be thread-mounted in the opposite end portions of the pintle structure and. project oppositely respectively upwardly and downwardly. The upward arranged screw element may be in the form of a hanger screw element and connected with overhead trolley means for pendantly supporting the accordian fold closure; in a similar manner, the lower tubular interior of a pintle structure may be fitted with a downwardly projecting guide screw, carrying a guide bearing, runningly received in grooveway structure in the horizontal sill of a folding closure installation for guidingly constraining the lower edge margin of the accordian fold closure. The improved closure configuration reduces substantially the cost of manufacture and increases the flexibility of installation and range of use of accordian fold closure structures incorporating slot and pintle slat connecting means.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 and 2 illustrate front elevational fragmentary views of the upper portion of the folding closure construction of the instant invention;

FIG. 3 is a vertical plane sectional view taken as on the line 3-3 of FIG. 1;

FIG. 4 is a horizontal plane sectional view taken as on the line 4-4 ofFIG. 1;

FIG. 5 is a fragmentary perspective view illustrating an upper thrust bearing means of the invention;

FIGS. 6 and 7 illustrate the lower front portion of the folding closure construction;

FIG. 8 is a vertical sectional view taken as on the line 8-8 of FIG. 6 and illustrating a particular configuration of the horizontal guide sill means of the folding closure;

FIG. 9, similar to FIG. 8, illustrates an embodiment of the folding closure structure adapted for installation as a curtain wall closure or the like, and illustrating particularly the guide sill rail means arranged along the level of a floor of a building (floor structure being shown in broken lines);

FIG. 10 illustrates another embodiment of the invention illustrating the folding closure construction as includinga pair of accordian fold closures, and as including lock means for releasably locking the pair of closures together;

FIG. 11 is a horizontal sectional view of the lock means of DESCRIPTION OF THE PREFERRED EMBODIMENTS The FIGS. 18 illustrate one embodiment of the folding closure construction, indicated 14, and illustrated mounted in a building wall 16. An accordian fold closure panel 18 is operably mounted in the building opening by header and sill rail means 20, 22 fixedly secured in horizontal parallel relation in the upper and lower margins of the building opening respectively by screw elements 24. Vertical side jamb members 26 (one shown) secured by screw means 28, may be fitted on opposite sides of the building opening, and provide vertical stationary element means framing the accordian fold closure 18 in the installation.

The folding closure 18 includes a plurality of alternatingly arranged edgewise hinged

vertical slat members

30, 32 connected together by a series of inside hinge joint connections 34 and a series of outside hinge joint connections 36. The hinge

joint connections

34, 36 each are generally of like form but conversely configured, for admitting of accordian fold movement of the closure panel. Each inside hinge joint 34 includes a pintle portion 34 extending vertically along an edge margin of a slat body 32, and a groove portion 34" extending along an edge margin of a slat body 30. The

slat members

32, 30 preferably are of extruded metal form and longitudinally uniform. The

slat members

30, 32 preferably are extruded with longitudinally extending reinforcing and ornamental rib portions 30', 32 extending symmetrically along opposite side face surfaces respectively of the slat members. The pintle portion 34' of each inside hinge joint 34 is generally of slotted tube form and defines an axial opening 34a and slot opening 34bextending coextensive the length of the slat member 32 (see FIG. 4). The semi-cylindrical exterior surface of the pintle structure 34' of slat member 32 snugly correspondingly engages the interior semi-cylindrical surface of groove structure 34" of the slat member 30.

Each outside hinge joint connection 36, corresponds in structure with each of the inside hinge joint connections 34 and includes a pintle portion 36' and groove portion 36" integrally formed respectively with the

slat body structure

30b, 32b of the

slat members

30, 32. The pintle portion 36' of each outside hinge joint connection 36 is likewise of semi-tubular form and defines an axial opening 364: and slot opening 36b extending coextensive the length of the

respective slat members

30, 32. If desired, the

slat members

30, 32 may be provided respectively with louver-like elements 30, 32' struck respectively from the

body structure

30b, 32b of the

slat elements

30, 32, and defining vertical series of downwardly oriented openings 30' 32".

The header rail means 20 is generally of tubular form and rectangular in cross section, defining a tubular interior 20'. The header rail 20 preferably is of extruded metal configuration, and formed with upwardly projecting coplanar upper and lower flange portions respectively 38, 38'. Screw elements 24 passing through the upper flange portion 38, threadedly engage the wall 16 and horizontally support the header rail 20. The lower flange 38 provides compression foot means for abuttingly engaging the vertical wall surface 16' and for maintaining the header rail in horizontal outstanding relation to the wall.

The header rail 20 defines an upwardly oriented longitudinally extending trackway defining parallel extending

dual trackway surfaces

40, 40 adapted to runningly support wheels 42', 42' of the folding closure trolley 42. The trolley per se is of substantially typical design and includes the pair of trolley wheels 42', 42 and trolley frame structure 42" journalling the trolley wheels in stationarily spaced configuration.

The hanger means pendantly supporting the folding closure panel from the trolley means 42 preferably includes a hanger screw 44 having a shank portion 44' threadedly fixed in the upper interior of the pintle structure 34 of each alternate inside hinge joint connection 34. Each hanger screw 44 preferably is of a self-tapping type and with its hardened shank portion 44' received in the upper interior of the axial opening 340 and fixedly embedded in the pintle structure 34' of the respective inside hinge joint 34. If desired, an annular plastic washer 46 may be placed underneath the screw head portion 44" and ridingly engaged with the upper surface of the trolley frame 42' The folding closure construction also preferably includes upper guide means for guidingly constraining the upper horizontal margin of the folding closure panel 18 during bidirectional movement and for maintaining the trolley 42 in a laterally centered disposition relative to the tubular interior 20 of the header rail 20: The header rail preferably includes a parallel spaced pair of depending

flange portions

48, 48 defining a confronting pair of guide surfaces adapted to opposingly engage opposite portions of an upper guide bearing 50 concentrically supported on a respective hanger screw 44. The guide bearing 50 preferably is annular in form and is interposedly supported by the screw 44, between the upper edge of pintle structure 34' and the underside of the trolley frame 42". The upper guide bearing 50 may be provided with an upper annular reinforcing shoulder portion 50'.

Each inside hinge joint 34 preferably is provided at the lower terminus thereof with a lower guide projection 52 operative in the upwardly facing grooveway 22 of the sill rail 22 (see FIG. 8). The series of lower guide projections 52 respectively of the series of hinge joint connections 34, are received in the lower guideway groove structure 22', 22 and provides means for guidingly constraining the lower edge margin of the closure panel in bidirectional opening and closing movement. Each guide projection 52 preferably includes a sleeve-like guide bearing 52' fixedly secured to the lower terminus of the pintle structure 34' of each respective hinge joint connection 34. A self-tapping metal screw 52" extends through the bearing 52' and threadedly engages the lower extension of the pintle structure 34'; the shank portion of the screw 52" is threadedly fitted in the lower interior of the axial opening 34a and clampingly secures the bearing 52' in a downwardly projecting disposition runningly engaging the opposite side surfaces 22", 22" of the sill rail structure. The bearing 52 may be provided with a pair of

annular rib portions

52a, 52a, providing anti-friction means for running engagement with the groove surfaces 22", 22". Each guide bearing 52 may also be provided with a hexagon shaped upper portion 52b, adapted for engagement by a Wrench or hand tool; the hexagon portion 52b may provide for additional leverage means when tightening or loosening the screw 52" and in assembly or disassembly of the closure structure.

The folding closure construction 14 (FIGS. 1-8) is adapted to be installed in a window opening at a disposition elevated above a floor or ground surface. The sill rail 22 is thus provided with oppositely projecting longitudinally extending upper and lower flanges 22a, 22b adapted to lie flush against the wall surface 16 (shown in broken lines in FIG. 8). The screw elements 24 preferably extend through the lower flange portion 22b of the sill rail and below the horizontal ledge 16" of the building opening. The sill rail 22 preferably includes a horizontal longitudinally extending face flange portion 22c projecting transversely obliquely outwardly and downwardly of the rail 22 and extending longitudinally along the lower margin of the building opening. It will be noted that the upper surface 520 of each guide bearing 52' engages the bottom edge surfaces respectively of the pintle and groove structure 34', 34; the series of bearing surfaces 520 provides axial thrust surface means receiving the downward thrust and weight of the closure panel, continuously and during the folding operation of the closure structure.

An upper bearing 54, and a lower thrust bearing 56 preferably is arranged at the respective upper and lower end portions of each outside hinge joint connection 36 and provides means for preventing relative axial displacement of the pintle structure 36 and groove structure 36" of each hinge joint connection between adjacent slat members 30, 32 (see FIGS. 3 and 8). The upper and

lower thrust bearings

54, 56 each are preferably of annular washer form and operatively engage opposite end edges respectively of the pintle and slot structure 36', 36". Self-tapping type thrust screw elements 58, 60 extend respectively through the bearing

elements

54, 56 and threadedly engage the pintle structure 36' of each outside hinge joint 36; the screw shank portions 58', 60' are received respectively in opposite ends of the axial opening 36a and are threadedly fixed in the respective upper and lower end portions of the pintle structure 36' of each outside hinge joint.

The header rail structure 20 preferably is extruded with an awning flange 62 extending along the horizontal extension of the header rail and projecting generally horizontally outwardly of said rail and arranged at a disposition projecting over the horizontal upper margin of the folding closure. An awning flange extension member 62' preferably is fitted on the upper surface of the flange 62 and fixedly secured thereto by rivet means 62". The awning flange extension 62' preferably is provided with a rolled proximal edge portion 62'a, extending longitudinally along the upper face surface of the header rail 20 and providing decorative or ornamental means for enhancing the appearance of the header rail structure. The accordian fold closure 18 may be laterally anchored in the installation by a hinge joint connection 34 extending along the inward vertical margin of side jamb 26 (see FIG. 4). Also, in certain installations of the closure construction, a vertical member 64 may be stationarily supported between the header and sill rails 20, 22 and provide abutment means for the leading slat member of the closure configuration when it is in an expanded closed disposition (see FIGS. 2, and 7).

FIG. 9 illustrates a folding closure construction 114 and an embodiment of the invention of curtain wall accordian fold form. The folding closure construction 114 includes an accordian fold closure panel 118 adapted to be operably supported with its lower horizontal margin being closely spaced above the level of a floor surface 166a. The folding closure construction 114, corresponds with the closure construction 14, and differs specifically in structure only in the configuration of the sill rail means 122: closure construction 14 includes a plurality of closure slat members 130, 132; a series of inside hinge joint connections 134; a series of outside hinge joint connections 136; a lower guide bearing and

screw unit

152, 152"; a lower thrust bearing and screw assembly 156, and, the remaining structure as specifically described in the folding closure construction 14. The sill rail member 122 is adapted for accommodating a split-level or stepped floor configuration 166a, 166b, 1660 and is extruded to form upper and lower horizontal wall portions 1220, 122b; parallel confronting wall portions 122', 122' defining the grooveway receiving the series of lower guide bearings 152; and includes an oblique face flange portion 122C. The sill member 122 is stationarily supported, preferably with its lower wall portion l22b and the distal edge 122a of the face flange restingly engaging the floor surface 166b and with the upper wall portion 122a edgewise engaging the vertical floor surface 166a and lying generally coplanar with the horizontal floor surface 166a.

The FIGS. -12 illustrate another embodiment of the folding closure construction, indicated 214, and an embodiment particularly representing the folding closure lock means 268 of the invention. The closure construction 214 preferably includes a convergingly divergingly operative pair of accordian fold closure panels 218, 218', arranged respectively leftward and rightward as viewed in the drawing. The

closure panels

218, 218 preferably include respectively half slat members 270, 270' hingedly connected respectively to slat members 232, 232' respectively by inside hinge joint connections 234, 234'. The half slat members 270, 270' are provided respectively with tongue and groove portions 270a and 27%, extendingvertically coplanar and operative for mating tongue and groove engagement when the

closure panels

218, 218 are in converged expanded configuration, as shown in the drawing. The half slat members 270, 270' are provided respectively with angle flange projections 2700, 270d; 270C, 270d, parallel extending and adapted for mating arrangement when the closure panels are in closed converged configuration; when the panels 218, 218' are in closed configuration, the angle flange portions 270c, 270c' are in flatwise mating engagement, and the

angle flange portions

270d, 270d are in coplanar arrangement (see FIGS. 11 and 12).

The lock means 268, adapted for locking the closure panels 218, 218' includes a lock lever 272 pivotally supported by fulcrum pin means 274a, 274b supported on the flange projection 270d of the half slat member 270. The lock lever 272 is pivotally fulcrumed on a horizontal axis on the vertical half slat element 270 and is normally in a locked horizontal disposition. The lock lever 272 is provided with a barbed head portion 272a adapted to extend through aligned

apertures

270e, 270e' formed respectively in the parallel arranged flange portions 270e, 2700 of the half slat members. The barb portion 272a of the lock lever defines a transverse lock surface 272b, adapted to hook over and engage a strike edge portion 270f of the aperture structure 270s of the rightward half slat member 270. Plunger and spring means 276, 278, fitted coaxially in aperture structure 2726 of the lock lever 272 provides means yieldably urging the lock lever barb portion 272 a clockwise as viewed in the drawings, and to a latched configuration; the plunger head portion 276a abuttingly engages continuously the flange portion 270C and yieldably turns the latch lever to a locked configuration. A handle projections 272d of the lock lever provides finger-operative means for manipulating the lock lever to an unlocked disposition. In convergingly moving the closure panels 218, 218' to closed configuration, the sloping undersurface 272a of the lever head portion 272a engages the strike edge 270f lifting the barbed head over the strike edge and latching the closure panels together. The fold ing closure construction 214 may be arranged in an open disposition by manipulating the lock lever 272 counterclockwise while divergingly moving the pair of closure panels.

While the instant invention is shown and described in presently preferred embodiments, it will be understood that various changes and modifications may be made in the embodiments as described without departing from the spirit and scope of the invention.

What is claimed is:

1. A folding closure structure comprising,

A. a closure panel of accordian fold configuration adapted to be bidirectionally slat from open to closed positions including,

l. a plurality of alternatingly arranged edgewise hinged,

extruded, vertical salt elements of uniform cross sectional configuration,

. a series of inside hinge joint connections,

. a series of outside hinge joint connections, said inside and outside hinge connections being alternatingly ar ranged and hingedly connecting respectively adjacent vertical closure slat elements, each of said inside and outside hinge connections being comprised of,

a. a groove, integrally extruded along one vertical edge of each of said slats in the form of a first tubular segment, the axis of which is radially disposed, along its length, in the plane of at least a portion of said slat,

b. a second tubular segment, similarly formed, along the opposed vertical edge of said slat, having a reduced diameter for sliding engagement, in pintle fashion, within said first tubular segment of the adjacent slat element;

B. a header rail means including,

1. a longitudinally extending upper trackway;

C. trolley means, operably supported on said trackway, in-

cluding,

l. a trolley frame means to operably support a plurality of trolley wheels,

2. a hanger screw member extending downwardly through each trolley frame and including a lower portion threadedly engaging axially within the upper end portion of each of said second tubular segments of each of said inside hinge joint connections;

D. an upper guideway groove defined by a spaced pair of parallel, horizontal flanges depending downwardly from said header rail means;

E. a plurality of upper guide bearing elements, each of which is supported on a respective hanger screw member between said guideway groove flanges;

F. a horizontal sill rail means fixed parallel to and in a generally vertical coplanar relation to said header rail means, said sill rail means defining an upwardly oriented lower guideway groove;

G. a lower guide bearing projection fixed to and extending downwardly, into said lower guidway groove, from the lower end of each of said second tubular segments of said inside hinge joint connections;

H. a vertical element arranged generally parallel to a leading vertical edge of the folding closure structure;

I. a relatively deep groove extending; along the entire height of said vertical edge;

J. a tongue along the opposed edge of said vertical element,

adapted to nest within said groove when said folding closure structure is moved to a closed position;

K. lock means for selectively maintaining said folding closure structure in the closed position including,

1. a latch lever pivotally fulcrumed on a transverse horizontal axis on said vertical element,

2. a barb portion projecting outwardly of said vertical element,

3. a transverse, horizontal strike edge defined in said leading edge, adapted to be lockinglly engaged by saidbarb portion when said folding closure structure is moved to the closed position,

4. compression spring means to hold said barb portion in said locked engagement.

2. A folding closure structure as set forth in claim 1 wherein each lower guide bearing projection includes a lower guide screw having a threaded distal portion received in the axial opening of said second tubular segment, and a lower guide bearing fitted on the shank portion of said lower guide screw within said lower guideway groove.

3. A folding closure construction as set forth in claim 2 wherein the lower guide bearings of said series of lower guide projection means includes axial thrust surface means receiving downward thrust and weight of said closure panel.

4. A folding closure construction as set forth in claim 1 wherein said header rail means includes awning flange means extending along the longitudinal extension of said header rail, projecting generally horizontally outwardly of said rail and arranged at a disposition substantially directly over the horizontal upper margin of said folding closure panel.

5. A folding closure construction as set forth in claim 1 wherein each joint connection of the series of outside hinge joint connections of the closure panel is of mating groove and pintle configuration and includes upper and lower thrust bearing means operative for preventing relative bidirectional contradirectional axial displacement of the mating pintle and groove structures of each outside hinge joint connection.

6. A folding closure structure as set forth in claim wherein an upper and a lower thrust screw assembly is arranged respectively at the upper and lower ends of each of said outside hinge joint connections, each of said upper and lower screw assemblies includes a screw having a threaded shank 5 portion received within the axial interior of said second tubular segment and a bearing ring interposed between a head portion of said screw and one of said ends.

UNITED STATES PATENT OF F ICE CERTIFICATEOF CORRECTION 7 Patent No. 3,670,797 7 i Dated June 20, 1972 -Inventor(s) John H. 58886110 ""It is certified that error appears in the above-i dentified patent and that said Letters Patent are hereby corrected as shown below:

i chan e "Assignee: WEATHER CONTROL SHUTTERS, INC.,

Broward County, Pa." to -Assignee: WEATHER CONTROL SHUTTERS, INC. Broward County, Florida-- Signed and sealed this 16th day of July 1974.

(SEAL) Attb'est:

McCOY M. GIBSON, JR. C. MARSHALL DAMN Attesting Officer 7 Commissioner of Patents USCOMM-DC B037 6-P69 FORM Po-mso (10-69) 3 Us, GOVERNMENT PRINTING OFFICE: IID 0-366-33

Claims

1. A folding closure structure comprising, A. a closure panel of accordian fold configuration adapted to be bidirectionally moved from open to closed positions including, 1. a plurality of alternatingly arranged edgewise hinged, extruded, vertical slat elements of uniform cross sectional configuration, 2. a series of inside hinge joint connections, 3. a series of outside hinge joint connections, said inside and outside hinge connections being alternatingly arranged and hingedly connecting respectively adjacent vertical closure slat elements, each of said inside and outside hinge connections being comprised of, a. a groove, integrally extruded along one vertical edge of each of said slats in the form of a first tubular segment, the axis of which is radially disposed, along its length, in the plane of at least a portion of said slat, b. a second tubular segment, similarly formed, along the opposed vertical edge of said slat, having a reduced diameter for sliding engagement, in pintle fashion, within said first tubular segment of the adjacent slat element; B. a header rail means including, 1. a longitudinally extending upper trackway; C. trolley means, operably supported on said trackway, including, 1. a trolley frame means to operably support a plurality of trolley wheels, 2. a hanger screw member extending downwardly through each trolley frame and including a lower portion threadedly engaging axially within the upper end portion of each of said second tubular segments of each of said inside hinge joint connections; D. an upper guideway groove defined by a spaced pair of parallel, horizontal flanges depending downwardly from said header rail means; E. a plurality of upper guide bearing elements, each of which is supported on a respective hanger screw member between said guideway groove flanges; F. a horizontal sill rail means fixed parallel to and in a generally vertical coplanar relation to said header rail means, said sill rail means defining an upwardly oriented lower guideway groove; G. a lower guide bearing projection fixed to and extending downwardly, into said lower guidway groove, from the lower end of each of said second tubular segments of said inside hinge joint connections; H. a vertical element arranged generally parallel to a leading vertical edge of the folding closure structure; I. a relatively deep groove extending along the entire height of said vertical edge; J. a tongue along the opposed edge of said vertical element, adapted to nest within said groove when said folding closure structure is moved to a closed position; K. lock means for selectively maintaining said folding closure structure in the closed position including, 1. a latch lever pivotally fulcrumed on a transverse horizontal axis on said vertical element, 2. a barb portion projecting outwardly of said vertical element, 3. a transverse, horizontal strike edge defined in said leading edge, adapted to be lockingly engaged by said barb portion when said folding closure structure is moved to the closed position, 4. compression spring means to hold said barb portion in said locked engagement.

2. a hanger screw member extending downwardly through each trolley frame and including a lower portion threadedly engaging axially within the upper end portion of each of said second tubular segments of each of said inside hinge joint connections; D. an upper guideway groove defined by a spaced pair of parallel, horizontal flanges depending downwardly from said header rail means; E. a plurality of upper guide bearing elements, each of which is supported on a respective hanger screw member between said guideway groove flanges; F. a horizontal sill rail means fixed parallel to and in a generally vertical coplanar relation to said header rail means, said sill rail means defining an upwardly oriented lower guideway groove; G. a lower guide bearing projection fixed to and extending downwardly, into said lower guidway groove, from the lower end of each of said second tubular segments of said inside hinge joint connections; H. a vertical element arranged generally parallel to a leading vertical edge of the folding closure structure; I. a relatively deep groove extending along the entire height of said vertical edge; J. a tongue along the opposed edge of said vertical element, adapted to nest within said groove when said folding closure structure is moved to a closed position; K. lock means for selectively maintaining said folding closure structure in the closed position including,

2. a barb portion projecting outwardly of said vertical element,

2. a series of inside hinge joint connections,

3. a series of outside hinge joint connections, said inside and outside hinge connections being alternatingly arranged and hingedly connecting respectively adjacent vertical closure slat elements, each of said inside and outside hinge connections being comprised of, a. a groove, integrally extruded along one vertical edge of each of said slats in the form of a first tubular segment, the axis of which is radially disposed, along its length, in the plane of at least a portion of said slat, b. a second tubular segment, similarly formed, along the opposed vertical edge of said slat, having a reduced diameter for sliding engagement, in pintle fashion, within said first tubular segment of the adjacent slat element; B. a header rail means including,

3. a transverse, horizontal strike edge defined in said leading edge, adapted to be lockingly engaged by said barb portion when said folding closure structure is moved to the closed position,

6. A folding closure structure as set forth in claim 5 wherein an upper and a lower thrust screw assembly is arranged respectively at the upper and lower ends of each of said outside hinge joint connections, each of said upper and lower screw assemblies includes a screw having a threaded shank portion received within the axial interior of said second tubular segment and a bearing ring interposed between a head Portion of said screw and one of said ends.