DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] With reference to FIGS. 1a-1c, an insulation tie of the present invention is shown. The insulation tie has a head 1, a shaft 2, and a tip 3.

[0015] The head 1 may be of any suitable shape, such as square, rectangular, or preferably round, and has a thickness of preferably about 1 to 5 mm, more preferably about 2 mm. The thickness is chosen to permit a fastener, for example a screw or nail, to be anchored into the head 1 for attachment of a veneer to the insulation tie in a manner that will be more thoroughly described hereinafter. The head 1 may have a diameter of preferably about 5 to 10 times the width of the shaft 2, more preferably about 7 times the width of the shaft.

[0016] The shaft 2 may be of any suitable polygonal cross-section, such as round or rectangular, but is preferably square. Preferably, the width of the shaft 2 is uniform and about ¼ the thickness of the sheet of insulation to be retained. The shaft 2 is preferably attached to the head 1 at substantially the center thereof. The shaft 2 is substantially perpendicular to the head 1 and the longitudinal axis of the shaft defines the longitudinal axis of the insulation tie. The length of the shaft 2 is preferably about 4 to 6 times the thickness of the sheet of insulation to be retained. Gussets 4 are attached to both the shaft 2 and the head 1 to strengthen the tie and help maintain the alignment of the shaft with respect to the head.

[0017] The shaft 2 has a tip 3 at the end of the shaft opposite the head 1. The tip 3 is narrower than the shaft and may be rounded, pointed, or wedge-shaped, preferably pointed or wedge-shaped. When the insulation tie is inserted through a sheet of insulation by impalement of the tie, the tip 3 elastically deforms the insulation to permit passage of the shaft 2 through the sheet. The width of the shaft 2 is chosen so that it may pass through the sheet in co-operation with the tip 3 without forming a hole. The insulation thereby conforms to the outside surface of the shaft 2 when inserted through the sheet. This allows the tie to fit snugly within the sheet and obviates the need for pre-forming holes to permit passage of the shaft 2, saving labour and allowing the position of the tie to be determined on-site.

[0018] The shaft 2 comprises a series of barbs 5 positioned at pre-determined longitudinal positions along the longitudinal axis of the shaft. The increment in longitudinal position between successive barbs 5 in the series need not be uniform. Each barb 5 may be of any suitable shape provided that a portion of each barb extends transversely from the shaft. Preferably, the barbs 5 extend a uniform pre-determined distance from the shaft. Preferably, the barbs 5 have a triangular cross-section and are wedge shaped. Each successive barb 5 in the series is rotated about the shaft 2 a pre-determined rotational increment from the immediately preceding barb. The rotational increment need not be uniform; however, preferably each successive rotational increment is 90 degrees. This arrangement helps ensure that a hole is not formed when the tie is inserted through the sheet of insulation. The series of barbs 5 further comprises counterpart barbs 6 juxtaposed 180 degrees about the longitudinal axis. Each barb 5 in the series therefore has a counterpart barb 6 at the same longitudinal position, but on the opposite side of the shaft 2.

[0019] The longitudinal position of at least one of the barbs 5 in the series, preferably the first barb 7, is pre-determined according to the thickness of the insulation to be retained. Preferably, the first barb 7 has a face that is substantially perpendicular to the longitudinal axis. The longitudinal position of the first barb 7 is pre-determined so that its face and that of its counterpart 8 rests against the surface of the sheet of insulation when the tie is fully inserted through the sheet. The longitudinal position of the next barb in the series may be pre-determined to accommodate a different thickness of insulation.

[0020] The tie may be manufactured of any suitable material that provides sufficient structural strength to allow the tie to be impaled through the sheet of insulation while allowing easy attachment of a fastener to the head 1. The head 1 and shaft 2 may be made from different materials. The preferred material of manufacture is a plastic and preferably the tie is manufactured as a single piece using a mold.

[0021] The preferred process for producing the insulation tie comprises providing a mold having a mold cavity having a shape complementary to the tie. The plastic may then be introduced into the mold by suitable means, for example injected into the mold using a piston or pump. The plastic is then solidified to form the tie using conditions suitable for the plastic chosen; for example, temperature and/or pressure conditions may be selected according to the type of plastic that allow the plastic to be introduced into the mold as a liquid and then changed to solidify the plastic. Suitable plastics include but are not limited to thermoplastics, for example polyolefins, such as polyethylene or polypropylene.

[0022] With reference to FIG. 2, a method for constructing an insulated cast concrete wall comprises a set of concrete forms comprising two opposing partitions 9, 10 set apart a pre-determined distance. The concrete forms are of the conventional type, typically rectangular and made of wood. The forms are generally transported to the site and setup in a manner that is known to those skilled in the art using a boom truck or similar means to place the forms on top of a pre-prepared concrete footing 11. A set of concrete forms comprising a series of opposing partitions 9, 10 may be assembled with the edges of the partitions 9, 10 adjacent to one another. The opposing partitions 9, 10 are set apart a distance corresponding to the thickness of the concrete wall to be cast plus the thickness of insulation. The opposing partitions 9, 10 may be held together by any suitable connecting means, for example connecting rods 12, that span the intervening space between the partitions. Each of the connecting rods 12 is attached at one end to one of the partitions 9 and at the other end to the opposing partition 10. The connecting rods 12 prevent the partitions 9, 10 from separating during the subsequent pouring of concrete.

[0023] A tie having a head 1, a shaft 2 attached to the head, and a pointed or wedge-shaped tip 3 on the shaft is inserted through a sheet of insulation 13. The tip 3 elastically deforms the insulation 13 to permit passage of the shaft 2 through the insulation as previously described. When the tie is inserted through the sheet of insulation, a portion of the shaft 2 extends beyond the insulation. The tie may be inserted on site by any suitable means, such as impact with a hammer or simply by applying pressure to the head 1 of the tie by hand. When the tie is fully inserted, the head 1 is directly adjacent a surface of the sheet of insulation 13; alternatively, the tie may be partially inserted and the insertion completed during the subsequent pouring of concrete. A plurality of ties may be inserted in any desired pattern at any desired spacing in each sheet of insulation 13.

[0024] After insertion of at least one tie, the sheet of insulation 13 is placed between the forms and secured adjacent the inside surface of one of the partitions 9. The sheet 13 is generally rectangular and similar in size to the partition 9 so that the sheet may preferably be secured by wedging it between the connecting rods 12. Optionally, the sheet 13 may be held in place by a clip (not shown) placed over the connecting rod 12 adjacent the inside surface of the sheet. A single sheet 13 may be inserted against one of the partitions 9 to insulate one surface of the wall or, optionally, a second sheet 14 may be inserted against the opposing partition 10 to insulate both surfaces of the wall, as shown in outline in FIG. 2.

[0025] The portion of the shaft 2 extending beyond the insulation 13 extends into a cavity 15 defined within the forms. The cavity 15 is defined by the interior opposing surfaces of the sheet 13 and either the sheet 14 or the partition 10, depending, respectively, on whether both surfaces or a single surface of the wall is being insulated. The tip 3 of the tie may terminate within the cavity 15 to prevent the tip from protruding through the wall. This is especially desirable when both surfaces of the wall are insulated. Within the cavity 15, steel re-bar 16 may be added to strengthen the wall. The re-bar 16 is generally comprised of cylindrical corrugated steel strips horizontally oriented within the cavity 15.

[0026] To form the wall, concrete is poured into the cavity 15 and cured. The concrete presses the insulation 13 firmly against the partition 9, completing the insertion of any partially inserted ties and counter-sinking the head 1 into the insulation until it is flush with the surface of the sheet. The concrete surrounds the re-bar 16 and the portion of the shaft 2 extending into the cavity 15. Upon curing, the concrete sets around the shaft 2 and the series of barbs 5 anchor the tie within the wall, thereby holding the insulation 13 securely in place. After the concrete has set, the forms may be removed and re-used.

[0027] With reference to FIG. 3, after removal of the forms a veneer 17 may be applied to the insulated surface of the wall 18. A wall that is insulated on one side only is shown in exploded view in FIG. 3, although the same principles apply if both sides are insulated. A veneer 17 may be placed adjacent the insulated surface 18 and fastened to the tie, for example by screwing into the head 1. The pattern and spacing of the ties are preferably uniform to facilitate attachment of the veneer 17. The screw 19 is fastened directly to the tie without the need for a pre-formed hole and the tie is not required to spread upon insertion of the screw. For the application of certain types of veneer 17, it may be desirable to apply strapping, for example strips of wood (not shown), to the surface of the sheet of insulation 18 before application of the veneer 17. The strapping is preferably fastened to the tie prior to fastening the veneer 17 to the strapping. The strapping is typically oriented horizontally with a single piece of strapping spanning several ties. For interior surfaces, the veneer 17 may include, for example, drywall, paneling, or plywood. For exterior surfaces, the veneer 17 may include, for example, vinyl or aluminum siding, corrugated steel and may further include bricks or stone masonry. The latter may require the use of specialized fasteners in addition to screws 19.

[0028] Other advantages which are obvious and which are inherent to the structure will be evident to one skilled in the art.

[0029] It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.

[0030] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.