Abstract: This invention is directed to a stretcher frame assembly for mounting fabrics such as are used by artists for mounting canvas for painting and other works. The stretcher frame comprises interconnected frame sections having ridges on the inner periphery thereof to which the edges of the fabric are secured by removable means such as spring clips. The stretcher frames are particularly suitable for use in art classes where such frames may be reused.

Abstract: A stretcher frame comprises a plurality of frame parts which face one another at their corner surfaces. A rotary stretching element has portions thereof extending into both recesses of opposing corner surfaces to prevent relative movement between the parts in a direction parallel to an axis of rotation of the stretching element. The stretching element includes a first bearing surface bearing against a wall of one frame part, and a second bearing surface bearing against a wall of the other frame part. The second bearing surface is non-symmetrical relative to the axis of rotation whereby the frame parts are spread apart in response to rotation of the stretching element.

Abstract: Stretcher bars are provided, each having face and rear mitered sections and a tongue therebetween, the tongue cooperating with a mitered section to define a slot. At least one tongue section of each stretcher bar defines a bevel on a portion thereof remote from the side defining the slot to facilitate ready entry of the tongue sections into slots of mating stretcher bars in non-interfering relationship with the tongue and miter sections of mating bars.

Abstract: A high efficiency particulate air filter is disclosed which comprises a frame surrounding and sealably supporting the filter pack, with the frame composed of four separate side panels which are rigidly interconnected at their abutting ends by means of corner plates. The corner plates are in the form of two flanges disposed at right angles to each other, and the flanges are closely received within slots formed on the outer face of the side panels. The corner plates preferably extend across the entire width of the side panels of the frame to impart substantial rigidity to the frame, and a sealing material is disposed in a recess which extends along the bight of the corner plates to provide a continuous seal along the abutting ends of the side panels.

Abstract: In a display or the like device, a flexible sheet is supported in tension within a frame by means of tensioning devices secured to the frame. Each tensioning device includes a movable peg which is engaged in an aperture in the sheet. Each peg can be placed in a position nearer the middle of the space within the frame in which it is retained, or displaced away from the middle of this space, to tension the sheet, and when so displaced, the peg is urged resiliently away from the middle of this space by a spring within the respective tensioning device, to hold the sheet in tension. The tensioning devices thus constitute a simple and compact means of providing for ready interchangability of various display areas in the frame.

Abstract: A screen printing frame is formed with hollow extruded metal frame members joined at their ends by extruded metal interfitting connectors which are retained within the ends of their associated frame members by frictional engagement supplemented by a bonding agent. The force required to establish the frictional engagement is maintained in the preferred embodiment by elastic flexure of a bowed side wall on each connector arm. The structural members may have prefinished surfaces such as anodized surfaces and are joined together without welding as would mar such surfaces during the welding operation. The amount of metal used for the extrusions has been minimized for cost reduction and to obtain a lightweight structure.Grooves on the interfacing surfaces of the connector arms and the frame members cooperate to form an interstitial lattice which receives a bonding agent. Miter joints at the corners of the structure are sealed by corner webs on the connectors in combination with a bonding agent.

Abstract: Joint for door frames or similar frame structures or sections, like window casements and frames, picture frames, etc. in which the sections that are to be jointed form an angle with each other or a direct extension to each other. On the outer or inner surfaces of these sections has been made an incision or a groove wherein a junction plate made of metal has been inserted. The junction plate is either corrugated, jagged, or toothed, whereby the effective thickness of the junction plate is made bigger or larger than the width of the groove in these sections, and such that the pressing of the junction plate into the groove causes it to be fixed in position. The inner edge of the junction plate, at least partly, comprises toothing or teeth, the teeth being pressed into the bottom of the groove at the end of the jointing.

Abstract: A portable display system having a plurality of hollow panel assemblies with each comprising two parallel and facing wall boards secured within a border strip device. Eight panel assemblies are hinged together to fold and unfold between a folded position in which all panel assemblies are in parallel stacked relation and an unfolded position in which the panels are open in any one of a number of different positions including a continuous wall arrangement.

Abstract: A foldable structure (2) and a method of manufacturing a foldable structure which, when folded produces a curved edge or corner. The structure comprises two panel members (32,34) having a respective edge region (18,20) which are adjacent and are spaced apart. Each edge region has a shoulder (8,10) and a curved portion (12,14). A flexible elongated bridging piece (22) is located between the shoulders (8,10) and defines a foldable region. A flexible lamina (24) covers a respective face of the panel members (32,34) and the flexible bridging piece (22).

Abstract: The present invention relates to slip joints for use with dampers, ducts, and mounting surfaces, as for example, fire dampers which are to be mounted through walls or other fire proof partitions and which are to have ducts mounted thereto. A novel duct-damper interface adaptor is disclosed which is constructed entirely from integral sheet material and which is slipped onto the inwardly depending flanges of a damper during the assembly of that damper. The damper adaptor unit is then ready to receive a complementally formed duct which is slidingly fitted thereon. This embodiment provides adaptors which are inexpensive, easy to manufacture, readily installable at the job site and provide superior advantage to the final damper-duct installation.

Abstract: The disclosure relates to one piece frames for fire dampers and the like. The frames are formed from elongate sheet metal blanks each of which is folded into a centrally open, generally rectangular form. In one embodiment, ends of the blank are secured together by a central tab on one end which extends through a T-shaped slot formed at the opposite end of the blank. In another embodiment, the blank is secured in its folded form by an angle shaped end bracket and the frame is provided with at least one corner bracket forming a gusset. The blanks have inwardly directed flanges which are formed with V-shaped notches to permit folding of the blank. In one embodiment, the notches each define an angle of less than 90.degree. and portions of the flange on each side of the notch are overlapped when the blank is folded to provide for frictional engagement between the overlapped portions. In another embodiment, the notches each define an angle of 90.degree.

Abstract: A fly screen for windows and doors comprising fly netting extending over one face of a rectangular frame with the marginal edge of the netting located in a recess in the frame and a wedge strip received in the recess over the fly netting to clamp and retain the fly netting in position. The fly screen may include mounting means for locating fly screen on an existing door or window or the fly screen may include separate mounting means for the frame whereby the fly screen can be mounted to cover an aperture. The fly screen frame comprises four frame elements formed as extrusions of the appropriate section which are cut to length with the adjacent ends being connected by corner cleats so that the fly screen frame can be assembled to suit any size of window or door. The fly netting comprises a material which can be easily cut such as plastic coated fiber-glass.

Abstract: A frame assembly for mounting and displaying a sheet of decorative fabric. The assembly is constituted by a set of four mitered pieces joined together at their corners by reinforcing snap-in elements to form a frame whose dimensions fall somewhat short of the sheet dimensions to an extent equal to the margins of the fabric sheet. Each frame piece is formed by an extruded molding having resilient inlet jaws which lie adjacent to the junction of the outer edge and the back of the molding and communicates with an internal storage channel running the full length of the molding. Also running the full length of the molding on the front face thereof is a band of pressure-sensitive adhesive having a peel-off cover. Formed in the back is a longitudinally-extending keyway.

Abstract: A portable display system having a plurality of hollow panel assemblies with each comprising two parallel and facing wall boards secured within a border strip device. Eight panel assemblies are hinged together to fold and unfold between a folded position in which all eight panel assemblies are in parallel stacked relation and an unfolded position in which the panels are opened in a continuous wall configuration.

Abstract: A corner key for securing channel members to form a frame, such as a gate frame which consists of two substantially identical mating members. Each of the members is in the form of two identical sections joined substantially at right angle to each other. There is at least one transverse groove on the face of each section which will mate with the other member so that when the mating faces of the identical members of the key are placed face to face apertures are provided in the corner key. These apertures are adapted to receive fastening means which tend to wedge the members apart thus creating a tighter fit in the channel member.

Abstract: A tight-fitting corner construction is provided for use between adjacent, integrally connected parts of a common panel. A specially configured, three-sided miter groove is formed between the panel parts, and the panel is folded to close the groove and to form a corner between the panel parts. An overhanging lip is provided on one of the panel parts along one side of the groove. When the panel is folded to form a corner, the lip is brought into overlying engagement with inner surface portions of the other panel part to effect a thorough, tight-fitting closure of the groove. The panel preferably comprises a hollow, elongated plastic member which is used to form the sides and back of a drawer frame. Snap-acting locking devices are carried in hollow portions of the panel adjacent the corner locations to lock the panel in its folded configuration. A drawer front carries connectors which project into hollow portions of the drawer sides.

Abstract: A corner clip for securing fins for a window product which extend outwardly from the sides. The corner clip is in the form of a base plate having two generally perpendicular legs each of which is defined by an inner and an outer side. Lips extend upwardly along the inner side of each leg and channels extend along the outer side of each leg. The lips engage a slot formed between the clip and the window product and the channels engage the edges of the fins. The length of each channel on each leg is at least as long as the length of the engaged portion of the lip.

Abstract: A free-standing, prefabricated, knock down, readily assembled and disassembled, relocatable vertical wall or space divider. Such wall dividers are useful for partitioning buildings and/or office complexes. The wall is made up of a plurality of individualized and decorative flush panel units which are interchangeable and which are adapted to be readily inserted within quadrilateral openings delineated by a novel wall frame and locked into place by hidden spline members that are mounted in the wall frame for translatory movement. The wall frame is fabricated in a novel assemblage of unique components which can present either a metallic or wooden exterior finish surface. The configuration of the wall frame components provides for lateral walls to extend outwardly not only at modular locations but also from any other desired location by use of novel adapters. The panels may be removed, redecorated and replaced as needed. Shelving or other appurtenances are attachable to the hidden spline members.

Abstract: A window assembly including parallel opposing tracks with a window having an overall width slightly smaller than the width between the leading edge of the tracks, the window being constructed of channel material interconnected at the corners by angle members, a first pair of angle members having inserted therein fixed pivot pins. The second pair of opposing angle members has assembled therein spring loaded latching members having projections adapted for engaging slots within the tracks.

Abstract: A screen door is provided having a spring-loaded adjustable bonnet on the top side or bottom side thereof, or both, and which includes two adjustment means which permit the bonnet to be set at any desired displacement from the top side or bottom side of the door to fit the door to a variety of doorway heights. Each adjustment means includes a serrated corner lock member which fits into the door frame and which serves firmly to lock the adjacent corner of the door frame, the corner lock member including an integral bushing which fits between two aligned holes in the door frame. Each adjustment means also includes an internally-threaded, headed sleeve which extends through one of the holes from one side of the door into the bushing, and an externally-threaded bolt which extends through the other hole from the other side of the door into the bushing, the bolt being threaded into the sleeve.

Abstract: The disclosure relates to a partition having vertical and horizontal frame members connected at a corner, each frame member having a web and side flanges each having a part extending inwardly to form with the web of panel receiving channel and a part extending outwardly to form a cap-receiving structure. Each frame member is provided with a pair of mounting flanges extending outwardly from the web, spaced from each other, and from the side flanges. The sides of each of the mounting flanges facing each other are provided with at least one groove. The frame members are mitered at the corners and abutted together so that their grooves meet at the corner. An angle member extends between the mounting flanges, fitting within grooves of the vertical and horizontal members of the corner and being connected to their webs to form a joint. A leg mounting bracket is provided extending between the mounting flanges and fitting within their grooves at the bottom of the vertical frame member and connected to each web.

Abstract: A frame has channel members extending along each edge of the frame material with each channel member abutting another member at the corner of the framed material. A locking member is slidable between the frame material and the pairs of abutting channel members at each corner of the frame material to hold the channel members together against the frame material. The channel members may have slots therein and the locking members may have protrusions to extend into the slots when the locking member is inserted between the frame material and the channel members. The frame material includes a transparent sheet for displaying an object therethrough and a rigid backing sheet on the other side of the object, and the channel members have a channel width substantially the same as the combined thickness of the transparent sheet, the object, the rigid backing sheet and the locking member.

Abstract: A drawer construction in which at least the sides and back are formed from identical hollow extruded plastics panels each provided with a longitudinal recess in the face thereof which will be innermost in use in order to accommodate a drawer bottom, and the panels being interconnected at right angles to one another by corner pieces engaged in the open ends of the panels. Detent means are preferably provided to retain the corner pieces securely in engagement with the open ends of the panels.