AU577694B2 - Prefabricated spacer and corner piece for multiple-glazed windows - Google Patents

Description

PREFABRICATED SPACER AND CORNER PIECE FOR MULTIPLE-GLAZED WINDOWS

This invention relates to insulated windows comprising two or more panes of glass, and is particularly directed to: an improved spacer of the type used for separating adjacent panes and for containing a dessicant material to control humidity in the air space-between the panes; to a method of manufacturing such spacers; and to improved corner pieces used to connect such spacers.

BACKGROUND OF THE INVENTION

Conventional insulated windows employ a plurality of panes of glass which trap air spaces between each pair of adjacent panes to serve a thermal insulation function. Elongated spacers are normally placed at the top, bottom and sides of each such air space to physically separate the adjacent panes.

A common problem with such multi-glazed windows, however, is that they are prone to clouding due to condensation of moisture which is trapped in the air spaces between adjacent panes. It is customary to deal with this difficulty by putting a dessicant material in the air spaces to sequester the moisture and thereby prevent condensation.

The usual practice is to use the spacers as containers for the dessicant material. The most common form of spacer is a piece of elongated sheet metal which has been folded up into a rectangular, hollow channel-shaped cross-section to define an interior compartment within which the dessicant is contained. Each spacer is provided with a row of openings communicating with the interior compartment thereof, and the spacers are installed with these openings facing the air space which is between the glass panes. This permits air exchange to take place between the air space and the interior compartments of the spacers, so that dehumidifcation of the air space by the dessicant inside the spacers can take place.

Insulated windows of the kind under discussion are often retrofitted to older buildings which are initially constructed with single-glazed windows. Installation of such retrofit windows may be done using spacers which are cut to size and filled with dessicant at the building site, or it may involve prefabrication of dessicant-containing spacers in standard lengths which exceed the dimensions of the windows. Such prefabricated spacers are later cut to the required shorter lengths at the time of installation.

For reasons of cost and convenience, the prefabrication approach is often preferred; but it has certain disadvantages which must be addressed. For one thing, the dessicant material inside the spacers must be protected from contact with ambient air until the time of installation; otherwise it would become saturated with moisture and be rendered nearly useless for the purpose of dehumidification.

For this reason, prefabricated spacers are usually provided with an adhesive tape which covers the air-exchange openings, and which is stripped off only when the spacer is installed. In addition, sealing plugs are provided at each end of the hollow spacer to physically retain the dessicant material inside the compartment and to prevent ambient moisture from entering through those ends.

U.S. Patent No. 4074480 of Burton is an example of a prefabricated, dessicant-containing window spacer of this type, which employs such sealing tape and end plugs to protect and retain the dessicatn prior to installation.

Other problems which afflict prefabricated spacers, and which are not recognized by Burton, arise as a result of the fact that at the time of installation the length of each standard^s-sized spacer must be reduced to fit the actual dimensions of the windows on which it is to be installed. When one end of a spacer is cut off for this purpose, the end plug which was located at that end is necessarily removed, and consequently the spacer then is liable to lose significant amounts of its dessicant material if care is not taken to prevent that material from falling out of the cut end.

In addition, once the end is cut off and the end plug thereby removed, all the dessicant material in the remaining portion of the spacer is exposed to ambient moisture entering through the cut end. Even though cutting of the prefabricated spacer to useable length is not done until shortly before installation, there still remains a significant time period after cutting and until all four of the spacers and the newly added glass pane are finally put in place, during which the entire dessicant content of the spacer is exposed to moisture contamination through the cut end.

After the spacers are cut to size, the end plugs are usually replaced with "corner" plugs which serve to join the upper and lower spacers to the side spacers at the corners of the window. But these corner plugs do not make a tight moisture seal against the walls of the dessicant compartment.

Exposure to ambient moisture during the installation procedure is a significant problem, because the useful life of a multi-glazed window (i.e. the number of years which elapse before it begins to exhibit condensation problems) depends strongly upon how much moisture contamination occurs during the period immediately prior to installation. Accordingly, any improvement in the moisture protection of the dessicant during this critical interval will result in a substantial improvement in the longevity of a costly retrofit installation.

U.S. Patent No. 4109432 of Pilz addresses the problem of physical loss of dessicant material, but does not recognize the more critical difficulty of moisture contamination. This patent discloses a plastic molded spacer having a hollow interior space for containing dessicant material. In addition, it suggests that: "The movement of the [dessicant material ... in a longitudinal direction within the hollow space ... can be prevented by suitable longitudinally spaced transverse walls or constrictions ..." (column 5, lines 14-17).

Such "walls or constrictions" may be effective to some extent in physically preventing the majority of the dessicant material from leaving the confines of the "hollow space." But mere "constrictions" are surely not enough of a barrier to moisture contamination; and even the "walls" mentioned by the Pilz patent are not specifically said to be made of a material having a significant moisture barrier effect.

Moreover, the plastic spacer of the Pilz patent is extruded; and the patent fails to disclose how such "walls" may be provided at "longitudinally spaced" locations in view of the continuous longitudinal flow which is characteristic of extrusion processes. In the absence of such information, it appears that the Pilz structure is not manufacturable, at least not economically and in volume, and therefore is not a practical solution to the problem of moisture contamination which occurs between the time that the prefabricated spacer is cut to length and the time that it is installed in the window.

It should also be noted that Pilz's plastic is an unsuitable material for spacers, not only because it is permeable to moisture, but also because those adhesives which work with glass are not suitable for plastics.

Another prior art approach to the problem of designing spacers which keep the dessicant material free of moisture contamination is seen in French Patent Application No. 82-02723 of Francis Bordonado, laid open under number 2,521,630 on August 19, 1983. The Bordonado device is an improvement over the type of prefabricated window spacer seen in the Burton and Pilz patents. It provides a spacer for use between window panes in multiple-glazed windows which comprises a selected length of elongated hollow container defining an elongated dessicant compartment therewithin. The selected length is greater than required for installation in a given window.

A dessicant material is distributed through the compartment, and air-exchange vents are provided for permitting the dessicant to communicate with the air space between window panels for dehumidifying purposes after installation of the spacer.

There are a plurality of partitions, maintained in sealing relationship with the interior walls of the compartment. The partitions are spaced at intervals along the length of the compartment so as to divide it into a plurality of sub-compartments. Consequently, the spacer may be cut to the required shorter length prior to installation in the multiple-glazed window without losing or exposing to ambient moisture the dessicant contained in any of the sub-compartments except the particular sub-compartment which is at the location of the cut.

The Bordonado patent application, however, does not disclose a commercially feasible method of manufacturing the spacer disclosed therein. It discloses three different types of partitions. The two types of partition illustrated in Figs. 2 and 4 of the Bordonado application must somehow be physically inserted into the interior of a substantially closed container, which appears to be physically impossible, or at the very least difficult to accomplish economically in the production of large quantities. The type of partition illustrated in Fig. 3 of Bordonado's application is injected from a hole in the side of the container, but this approach also seems impractical because there is no assurance that the partition material thus injected will push aside all of the dessicant material in its path and make an effective sealing contact with the opposite wall of the container.

Generally, the prefabricated spacers used in multiple-glazed windows consist of pieces of elongated sheet metal folded into a hollow cross-sectional shape to define the interior compartment within which the dessicant is contained. Each corner piece which is used to connect adjacent spacers together at the time of installation is formed with a horizontal leg and a vertical leg disposed at a 90 degree angle, each leg being inserted into the end of one of the adjacent spacers to hold the two adjacent spacers together and in perpendicular relation to one another.

When each leg of the corner piece is inserted into a spacer, a sealing compound is applied around the corner piece and spacers in order to seal any gaps by which ambient moisture could enter. But moisture leakage problems nevertheless arise when, due to changes in temperature and air pressure, the spacers pull away from the corner piece, creating openings through which ambient moisture can enter.

Conventional corner pieces are usually solid metal or plastic bodies with rounded, blunt or squared-off ends. When, used with the Bordonado type of spacer, described above, the rounded or blunt ends run up against the partitions. The corner piece then will not be able to fit all the way into the spacer, or may push the nearest partition out of place.

BRIEF SUMMARY OF THE INVENTION The present invention provides an improvement over the type of corner pieces commonly used with prefabricated window spacers. It provides a corner piece with ends having cutting edges to cut past the partitions inside the spacers. The corner piece is preferably also formed with a hollow portion facing outwardly so that it can be filled with sealant after assembly of the spacer frame. Some forms of the invention are also able to fit a greater variety of cross-sectional shapes of spacer members. Such a corner piece may be made from aluminum, copper, zinc or some other ductile metal. Molded plastic may also be used, but is not preferred because of thermal expansion incompatibilities. Sheet metal may be extruded, or folded into a channel or some equivalent hollow shape, and then bent into a 90 degree angle. The hollow portion of the channel is facing outwardly after it is bent to the proper angle. Certain shapes, such as a T or equivalent, make the corner piece useful for a wider variety of spacer cross-sections, particularly non-rectangular channels.

The outwardly facing hollow allows the interior of the corner piece, as well as the inside of the spacer, to be filled with sealant, creating a more effective seal.

Each end of the corner piece has a cutting edge, which may be raked at an angle to assist the corner piece in cutting past the partition. The partition will then form a seal against the corner piece which has cut past it.

The invention also provides an elongated hollow window-pane spacer, defining an elongated substantially closed dessicant-containing compartment therewithin, the compartment having a plurality of partitions in sealing relationship with the interior walls thereof and spaced at intervals so as to divide the length of the compartment into a plurality of subcompartments substantially isolated from each other for the purposes of moisture diffusion and physical retention of the dessicant.

The invention also provides a method of manufacturing such a spacer, which comprises the steps of folding longitudinal edge portions of a sheet to form flaps at an angle to the sheet, so that the flaps form the side walls of an open channel adapted to receive the dessicant and the partitions. Then the dessicant and the partitions are loaded into the open channel, after which a longitudinal edge portion of at least one of the flaps is folded at an angle to that flap to divide the flap into a side panel and a top panel, the top panel then abutting the other flap to close the channel and thereby form the substantially closed dessicant-containing compartment.

The features and advantages of the invention will be more fully appreciated from the following drawings and detailed description of illustrative embodiments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a retrofit multi-glazed window spacer in accordance with this invention, the rightmost portion thereof being illustrated in finished condition and those portions which are further to the left being illustrated in progressively earlier stages of manufacture, so as to represent the method of manufacturing this spacer in a schematic fashion.

Fig. 2 is a longitudinal sectional view of the same spacer in finished condition, with one end thereof having been severed so as to cut the spacer to the appropriate length for installation in a window.

Fig. 3 is an end elevational view of the spacer of Fig. 2, looking from the cut end thereof. This figure also includes parts in phantom to further clarify the manufacturing process schematically illustrated in Fig. 1. Fig. 4 is a fragmentary perspective view of the spacer of the preceding figures installed in a window.

Fig. 5 is a perspective view of a corner piece in accordance with this invention in position for insertion into two adjacent spacers. Fig. 6 is a side elevational view of the corner piece being inserted into the adjacent spacers.

Fig. 7 is a side elevational view of the corner piece and spacers fully assembled.

Fig. 8 is a side elevational view of the corner piece of Fig. 5.

Figs. 9, 10, and 11 are elevational views of alternative embodiments of corner pieces in accordance with this invention.

Figs. 12-18 are cross-sectional views of alternative corner pieces in accordance with this invention.

Fig. 19 is a cross-sectional view of a mechanism for producing a corner piece in accordance with this invention in one step by die-stamping a piece of sheet metal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a spacer 10 (see Fig. 4) which is adapted to be installed in a window 12. Typically the window is of the uninsulated or single-glazed type comprising a single pane of glass 14. In order to convert such a window to the insulated or double-glazed type, a second pane 16 is added on the indoor side of the first pane 14. The two panes then trap between them an air space 18 which serves the purpose of thermal insulation. It is necessary, however, to keep the air in the space 18 dehumidified so that moisture condensation does not occur and the building occupants are thus able to see clearly through the window. The primary function of the spacer 10 is to physically maintain the panes 14 and 16 at the correct distance to define the width of the insulating air space 18. Thus, one such spacer, as seen in Fig. 4, is mounted at the top surface 20 of the window casement. Others, not visible in the drawings, usually are similarly typically mounted at the bottom and at both sides of the casement. All of the spacers 10 are in contact with the panes 14 and 16, and it is a common practice to provide thin layers 22 of a sticky poly-iso-butylene adhesive material on those surfaces of the spacers which abut the glass panes. This adhesive serves to keep the spacers in contact with the glass panes and also acts as a barrier to the entry of moisture into the insulating air space 18 from the outside environment. But during the process of installing the second pane of glass 16 in the window 12, some moisture is always trapped within the insulating air space 18, since the ambient air inevitably bears some moisture load at the time the retrofitting operation is carried out. The industry normally deals with this problem by making the spacer 10 hollow, and filling its interior with a dessicant material 24, such as powdered silica gel, which is capable of dehumidifying the insulating air space 18.

In order to permit this dessicant to come into contact with the air within the space 18, the surface of the spacer 10 which faces the air space 18 is provided with a row of holes 26 which are too small for the dessicant particles 24 to escape, but large enough for complete air interchange between the air space 18 and the interior of the spacer 10 to occur over an extended period of time.

Spacers of the type described are often prefabricated at factory locations, and later installed either at the factory or at the site of a building where a retrofit operation is being carried out. Such prefabricated spacers are likely to be precoated on opposite sides with the adhesive material 22, and that material in turn is covered with strips of release paper 23 which protect the adhesive material and are removed just prior to installation of the spacers.

Similarly, the surface of each spacer 10 where the air-exchange openings 26 are .located is preferably covered with a strip of adhesive tape 27, preferably of a moisture-barrier material, in order to prevent the absorption of ambient moisture by the dessicant material 24 before the spacer is installed. Just prior to ^installation, the adhesive tape is removed to expose the holes so that thereafter air exchange can take place for the purpose of dehumidifying the air space 18.

The prefabricated spacers 10 are made in standard lengths which exceed the window dimensions expected to be encountered, and then are cut to fit the windows at the time of installation. In the past a plug was provided at each end of a standard length prefabricated spacer in order to prevent the dessicant 24 from falling out of the spacer. Such plugs also provided a measure of protection against the entrance of ambient moisture into the dessicant-containing interior of the spacer prior to installation.

But when cut to length, such prior art prefabricated spacers were thereby deprived of their end plugs at the cut-away ends, and that end then constituted an opening through which the entire dessicant content of the spacer was subject to physical loss as well as contamination by ambient moisture.

In accordance with this invention, therefore, a means is provided for dividing the dessicant-containing interior compartment 40 of .the spacer 10 into a large number of separate sub-compartments 40A, 40B, 40C, 40D, etc., so that when one end of the spacer is cut off, only the particular sub-compartment 40D which is located at the place of the cut is opened thereby. That sub-compartment is subject to physical loss and ambient moisture contamination of its dessicant; but the other compartments are not. The desired compartmentalization is preferably achieved by installing within the interior of the spacer 10 a plurality of longitudinally spaced partitions 30.

The spacer 10 comprises an outer shell which is preferably formed of an elongated strip 31 made of sheet metal, for example aluminum, which is folded to form a tubular channel of rectangular cross-section. The hollow interior of the channel defines the dessicant-containing compartment 40. As seen in Fig. 3, the outer shell of the spacer 10 is initially in the form of a flat sheet extending from one longitudinal margin 32 to the other such margin 34.

Subsequently marginal portions of the sheet 31 which define panels 35, 36 and 37, 38 are folded vertically upwardly as indicated by arrows A, and the portions which define panels 35 and 37 are then folded horizontally as indicated by arrows B (see also arrows C in Fig. 1) , thereby forming the desired rectangular channel configuration which defines the interior compartment 40 for containing the dessicant material 24.

Rows of semicircular indentations 42 are formed on the opposite longitudinal margins 32 and 34 of the sheet 31 (see Figs. 3 and 1), and when the folding operation is concluded the indentations located on these opposite margins match up to form the air-exchange holes 26 (see Fig. 4) . The opposite margins may be spot-welded together, at locations between the air-exchange holes 26, to complete the assembly of the rectangular shell formed by the metal sheet 31.

The sequence of steps by which the spacer 10 is manufactured is schematically illustrated in Fig. 1. The flat metal sheet 31 moves from left to right, as indicated by arrows 44, while conventional metal-forming dies (not illustrated) fold the flaps 35, 36 and 37, 38 vertically up from the bottom panel 48, and then fold the flaps 35 and 37 horizontally inward, as illustrated by arrows C, to form the rectangular shell enclosing the dessicant compartment 40. After the flaps 35, 36 and 37, 38 are folded up into a generally vertical attitude, but before they are folded into their final position and before the flaps 35 and 37 are folded horizontally inwardly, the partitions 30 are placed within the channel formed by the flaps 35, 36 and 37, 38; and a nozzle 46 then delivers a charge of powdered dessicant 24 into each of the sub-compartments 40A, 40B, 40C, 40D, etc. defined between each pair of adjacent partitions 30.

The partitions 30 are preferably rectangular blocks of a firm but elastically compressible rubbery material, the chemical nature of which is such that it forms an effective moisture barrier. Butyl rubber is the preferred material, although latex rubber may also be acceptable in many applications. Such materials are capable of being compressed tightly by the folding of the sheet metal panels 35, 36, 37 and 38 to hold them firmly in place and to form a dessicant-retaining and moisture-tight seal between the partitions 30 and the folded metal sheet 31.

Thus after each partition 30 is inserted into the compartment 40, the adjacent portions of the panels 36 and 38 are folded to their final vertical positions and in the process are clamped tightly and compressively against the adjacent sides of the partitions. Then the panels 35 and 37 are folded horizontally inwardly and in the process these panels as well as the opposing or bottom panel are clamped tightly and compressively against the upper edges of the partitions 30. This serves to hold the partitions tightly in place between the side panels 36 and 38, and also between the top panels 35, 37 and the bottom panel 48, in order to retain the partitions in place and to form a tight seal ^■ against the passage of moisture into, and the escape of dessicant material 24 from, the sub-compartments 40A, 40B, 40C, 40D etc. The moisture barrier material of the partitions 30 thus cooperates with the tight compressive fit at all four edges of each partition to prevent leakage of moisture from any one of the sub-compartments to any other.

The adhesive tape 27 is then applied over the upper surface of the top panels 35 and 37 to seal off the air-exchange holes 26. In addition, the adhesive layers 22 are applied over the side panels 36 and 38, and the release paper strips 23 placed thereover. The tape 27 and release paper strips 23 remain in place until the spacer 10 is installed.

The spacers 10 are manufactured in standard lengths which exceed the largest window dimension expected to be encountered, and then are cut to the lengths required for each particular window at the time that they are installed. The spacing between each pair of adjacent partitions 30 is selected to be small in relation to the overall length of the spacer 10. As a result, when the spacer is cut to the required smaller length by a blade 50, as illustrated in Fig. 2, and the integrity of one sub-compartment 40D is disrupted thereby, only a small fraction of the total length of the spacer 10 is affected.

Thus only a small fraction of the total content of dessicant material 24 of the spacer 10 is lost through the cut end 52. Moreover, because of the tight compressive fit between all four edges of the elastic rubber partitions 30 and the metal shell 31, none of the dessicant material 24 is able to escape from the adjacent sub-compartment 40C.

In addition, even though the ruptured sub-compartment 40D is thus exposed to ambient humidity, none of that humidity can pass from sub-compartment 40D through the adjacent partition 30 into the adjacent sub-compartment 40C or any of the other individually sealed sub-compartments 40A, 40B, etc. during the installation procedure.

Consequently, physical loss of dessicant material, as well as contamination thereof by ambient moisture during the retrofit procedure, is limited to a small fraction of the total, i.e. the relatively small amount of dessicant contained in the one sub-compartment 40D as compared to the much larger amount contained in all the other sub-compartments 40C, 40B, 40A etc. which make up the entire remaining length of the spacer 10. As a result, the great majority of the dessicant material originally contained in that portion of the spacer 10 which is actually installed in the window 12 is preserved against these hazards, with the result that the useful life of the multi-glazed window 12 after retrofit is greatly increased. The present invention also provides a corner piece 110 (Fig. 5) which is adapted to connect adjacent hollow spacers 10A and 10B at right angles to each other for use in a thermally insulated window. In the past, a plug was provided at each cut end of the spacers to keep the desiccant material 24 from falling out. When the spacer was cut to size, the open ends of the spacer were fitted with L-shaped corner pieces of a prior art tye to connect top, bottom and two side spacers at right angles to form a rectangular spacer frame.

In the past, corner pieces were formed with blunt ends. A problem arises when the spacer described above is used with such blunt-ended corner pieces, because the latter could only be inserted part-way into the spacers 10A and 10B before they were blocked by the first partitio 30. Therefore, some means must be provided for the ends of the corner piece 110 to get past any partition 30 it encounters.

Corner pieces 110 are formed with a vertical leg 120 and horizontal leg 122 at a right angle thereto. They are preferably made of a ductile metal such as zinc or aluminum, but may also be molded of a plastic material. The vertical and horizontal legs of each corner piece 110 are aligned with the ends of adjacent spacers 10A and 10B (see Figs. 5 and 6) and inserted as seen in Fig. 7, thereby connecting top, bottom and side spacers to form a rectangular spacer frame. In the past, the corners of a thermally insulated window have been the weakest point of the window, i.e. the most prone to moisture leakage, thereby significantly decreasing the useful life of the window.

In accordance with the present invention, the corner piece 110 is made of a sheet-thin material formed with an open cross-section (for example, channel-shaped) so as to provide cutting edges 130 and 131. The cutting efficacy of edges 130 is preferably enhanced by raking the edge to about a 45 degree angle, thus forming sharpened points 134 (see Fig. 6) .

When the spacers 10A and 10B are cut to size to fit the window in which they are being installed, and the corner piece 110 is inserted thereinto, the cutting edges 130 and 131 of the corner piece 110 will be able to cut around the partition 30 without dislodging it, and the partition will form a seal against the corner piece 110, thereby preventing exposure of desiccant 24 to ambient moisture.

The preferred form of corner piece 110 is that seen in Figs. 5 through 8 and 12, which has the U-shaped open channel cross-section illustrated in Fig. 12, including a central member 140 and side members 142 upstanding therefrom. The cutting edges 130 are formed at opposite ends of each side member, and the cutting edges 131 are formed at opposite ends of the central member 140.

The cross-sectional shape of the corner piece 110 can be formed by extrusion, or alternatively from a piece of flat sheet metal by first folding the side members 142 out of the plane of the central member 140 to define the U-shaped configuration. In either case, the corner piece is subsequently bent into a right angle to define the two legs 120 and 122. The metal of which the corner piece is made must be sufficiently ductile for the side members 142 to stretch around a corner when the latter operation is performed.

In addition to permitting the corner piece 110 to cut its way past the partition 128, the open cross-sectional shape of the corner piece serves an additional function: it provides an interior cavity 144 (Fig. 12) between confronting side members 142. A sealing compound can be injected into the cavity 144 and into the interior of the hollow spacers 10A and 10B (between the partitions 30 thereof) even after the spacer frame has been assembled as indicated by Fig. 7. This additional sealing compound greatly improves the moisture penetration resistance of the corner region compared to prior art structures.

Therefore, after the corner piece 110 is fully inserted (see Fig. 7) , thereby joining the spacers 10A and 10B, sealant is injected into the cavity 144 in sufficient quantities to fill the spacers 10A and 10B up to their respective partitions 30, and also to fill the portion of cavity 144 which lies between the ends of the spacers 10A and 10B (see Fig. 7) .

In order to permit such injection of sealant, it is essential that the corner piece have a U-shaped channel shape or other open cross-section in which the hollow side faces outwardly, to permit the sealant to be injected into the interior of the spacers 10A and 10B and the cavity 144 of the corner piece 110 after the spacer frame is assembled.

When the corner pieces and spacers expand and contract with changes in temperature, they tend to pull away from the window frame, thereby causing a moisture-admitting gap in the corner area. With the present invention, the leakage of ambient moisture is minimized because of the presence of the sealant in the cavity 144, which adheres to the surrounding surfaces despite thermal expansion and contraction.

The profile of the corner piece 110 seen in Fig. 8 is not the only one which is feasible. The profiles of Figs. 9 through 11, among others, may also be used. In the profile of Fig. 9 the edges 130 are reaked in both directions to form a centrally located point 150 instead of the point 134. In Fig. 10 the walls 140 are foreshortened so that edges 130 are located behind edges 131. In Fig. 11 the edges 130 are curved concavely for still greater cutting efficacy.

Similarly, the cross-sectional shape of the corner piece 110 illustrated in Fig. 12 is not the only one which is feasible. Those of Figs. 13 through 18 will also work satisfactorily. The cross-section seen in Fig. 14 is a simple T-shaped channel, in which a base member 152 is welded to a wall member 154. Fig. 15 depicts a double folded or extruded T-shaped channel, and Fig. 16 a double T channel similar in construction to the embodiment of Fig. 14. Fig. 17 shows a folded or extruded triangular cross-sectional channel configuration. And Fig. 18 shows a folded or extruded L-shaped cross-sectional channel configuration.

The cross-sectional shapes of Figs. 13 through 17 have a particular advantage, in that they fit within various non-rectangular cross-sections of hollow spacers, indicated by dashed lines 160 through 162, which are commonly employed in the industry, as well as within the rectangular cross-section spacers 10A and 10B. Thus, the double T configuration of Fig. 13, the simple T of Fig. 14, and the triangular shape of Fig. 17 fit within the triangular spacer outline 160 and the curved triangular shape 161. Similarly, the double T shapes of Figs. 15 and 16 fit within an indented rectangular spacer outline 162. This greatly simplifies the inventory of corner types which must be stocked.

Fig. 19 illustrates a male die 170 and a female die 172 designed for die-stamping the corner piece 110 of Figs. 5-9 and 12 in a single operation from a continuously fed piece of ductile sheet metal 174. A male boss 170A on die 170 forms the U-shaped cross-section seen in Fig. 12 by cooperating with a female cavity 172 on die 172. Dies 170 and 172 are formed with complementary right angle vertices 176 to bend the corner piece into the desired right angle shape at the same time that the U-shaped cross-section is formed. The sheet 174 may be fed in the direction indicated by arrow 178 to make the process continuous. Each newly formed corner piece may be severed from the sheet 174 as it is stamped out by the dies 170 and 172.

It will now be appreciated that this invention provides an improved form of partitioned spacer, and a practical method for the mass production of such spacers; as well as an improved corner piece to be used with such spacers; all of which have significant advantages in the retrofitting of multi-glazed windows.

Claims (1)

1. THE INVENTION CLAIMED IS:

   1. A corner piece for joining two hollow window spacers, comprising two legs at an angle to each other, the outer extremity of each leg being formed of sheet-like members terminating in cutting edges.

   2. A corner piece as in claim 1 wherein said sheet-like members cooperate to define a cross-sectional shape which is open in an outward direction to permit injection of sealant thereinto after assembly with said spacers.

   3. A corner piece for joining adjacent spacer members, said corner piece comprising: a vertical leg and a horizontal leg; and cutting edge means on the ends of each leg for cutting around a partition.

   4. A corner piece as in claim 3 wherein: said cutting edge means is raked to form an angle which facilitates cutting.

   5. A corner piece as in claim 3, wherein: said corner piece is formed of ductile sheet material formed into a channel configuration; the interior of said channel configuration facing radially outwardly of the angle of the corner piece to allow sealant to be injected into said channel and into the spacer members after the corner piece is installed. 6. A method of forming an elongated sheet into an elongated hollow window-pane spacer defining an elongated substantially closed dessicant-containing compartment therewithin, and providing said compartment with a plurality of partitions in sealing relationship with the interior walls thereof and spaced at intervals so as to divide the length of said compartment into a plurality of subcompartments substantially isolated from each other for the purposes of moisture diffusion and physical retention of the dessicant; said method comprising the steps of: folding longitudinal edge portions of said sheet to form flaps at an angle to said sheet, whereby said flaps form side walls of an open channel adapted to receive said dessicant and said partitions; loading said dessicant and said partitions into said open channel; and folding a longitudinal edge portion of at least one of said flaps at an angle to said one flap to divide said one flap into a side panel and a top panel, said top panel then abutting said other flap to close said channel and thereby form said substantially closed dessicant-containing compartment. 7. A method as in claim 6, wherein longitudinal edge portions of both of said flaps are folded at angles to their respective flaps to divide both of said flaps into respective side panels and top panels, said top panels then abutting each other to close said channel and thereby form said substantially closed dessicant-containing compartment.

   8. A method as in claim 7, wherein said top panels abut each other along said longitudinal edges of said sheet.

   _t 9. A method as in claim 6, wherein the longitudinal edge of at least said one flap is formed with spaced indentations adapted to form vent holes for air exchange with said substantially closed dessicant-containing compartment.

   10. A method as in claim 9, further comprising the step of mounting removable closure means over said vent holes.

   11. A method as in claim 6, further comprising the step of applying an adherent sealant material to the exterior of said side panel. 12. A method as in claim 11, further comprising the step of mounting a releasable cover over said sealant material.

   13. A window-pane spacer manufactured by the method of claim 6.

   AMENDED CLAIMS

   [received by the International Bureau on 2 September 198.6 (02.09.86); original claims 1-3 and 5 amended; new claims 14-23 added; other claims unchanged (4 pages)]

   1. A corner piece adapted for joining two hollow window spacers at least one of which is of the type containing a desicσant and at least one partition, said corner piece com¬ prising two legs at an angle to each other, the outer extremity of at least one leg being formed of a sheet-like member terminating in a cutting edges of sufficient sharpness to readily cut said partition.

   2. A corner piece as in claim 1 wherein said corner piece has a cross-sectional shape which is open in an outward direction relative to said angle, whereby to permit injection of sealant into said open corner piece after assembly with said spacers.

   3. a corner piece adapted for joining adjacent spacer members, at least one of which is of the type containing a desiccant and at least one partition, said corner piece com¬ prising: a vertical leg and a horizontal leg; and cutting edge means on the end of at least one leg which is of sufficient sharpness for readily cutting said partition. 4. A corner piece as in claim 3, wherein: said cutting edge means is raked to form an angle which facilitates cutting.

   5. A corner piece as in claim 3, wherein: said corner piece is formed of ductile sheet material formed into a channel configuration; the interior of said channel configuration facing radially outwardly of the angle of said corner to allow sealant to be injected into said channel and into the spacer members after said corner piece is installed.

   12. A method as in claim 11, further comprising the step of mounting a releasable cover over said sealant material.

   13. A window-pane spacer manufactured by the method of claim 6.

   14. A corner piece as in claim 3 having a substantially U-shaped cross-sectional shape.

   15. A corner piece as in claim 3 having a substantially T-shaped cross-sectional shape.

   16. A corner piece as in claim 15 wherein said T-shaped cross-section is folded to form a double-thickness center leg.

   17. A corner piece as in claim 15 wherein said T-shaped cross-sectional has two center legs.

   18. A corner piece as in claim 17 wherein said center legs are folded to achieve a double thickness.

   19. A corner piece as in claim 3 having a substantially triangular cross-sectional shape.

   20. A corner piece as in claim 3 having a substantially L-shaped cross-sectional shape. 21. A corner piece as in claim 1 wherein it is connected to: at least two hollow window spacers, at least one of which is of the type containing a desiccant and at least one partition;

   each of said legs of said corner piece being received within a respective one of said spacers whereby said corner piece assembles said spacers into an angular relationship with each other; and

   said cutting edge is cuttingly engaged with said partition in the interior of said hollow spacer.

   22. The corner piece in claim 21 in which said edge is of sufficient sharpness to readily cut said partition.

   23. The corner piece as in claim 21 wherein said corner piece has a cross-sectional shape which is open in an outward direction relative to said angle, whereby to permit injection of sealant into said open corner piece when it is assembled with said spacers.