# Patent

## Title
Anti-sag hinge

## Abstract

There is disclosed an anti-sag hinge (10) which includes a mounting flange assembly (12) pivotally coupled to a strap assembly (15). The mounting flange assembly includes a mounting flange (16) having four mounting holes (17) therethrough, a lower hinge barrel (18) extending from the mounting flange, and a removably mated upper hinge barrel (19) extending from the mounting flange. The upper and lower hinge barrels provide for a dual or double shear system (two positions wherein a shearing force is provided between the strap assembly and the flange assembly 12) that provides a stable connection between the strap assembly (15) and the flange assembly (12). The strap assembly includes a strap (31) extending from a cylinder portion (32).

## Background
TECHNICAL FIELD
This invention relates generally to door hinges, and more particularly to double shear type anti-sag hinges used for commercial refrigerator and freezer doors.
BACKGROUND OF INVENTION
Walk-in cold rooms, such as walk-in coolers, freezers, or other refrigerated environments, are common in various industries, including supermarkets and grocery stores, commercial kitchens, and other food service facilities. They typically have one or more access doors for entry and exit.
These doors are heavy and thus a common problem that may occur over time is door sag, which may cause the door not to open freely as it drags against the underlying floor or be properly locked or sealed as it does not fully close. The sag is caused by hinge wear, structural shifting due to temperature cycling, impacts, abuse, poor design of the door and frame, or the hinges shifting on the mounting screws. Sag is difficult to overcome without extensive repair work, such as the removal and remounting of the hinges or the replacement of the door and frame. For the replacement, adjustment or cleaning of the hinge the NSF prefers that the hinge be a “lift-off” type to allow the door and the enclosure to be cleaned by lifting it off the hinges and hosing down the door assembly. Most lift off hinges are of a cantilever style that includes a single shear system. Single shear system hinges however are prone to wear due to the forces exerted upon the cantilevered hinge.
Accordingly, there is a need in the art for a hinge that will allow for the door to be lifted off easily and which does not promote door sag. It is to the provision of such therefore that the present invention is primarily directed.
SUMMARY OF THE INVENTION
In a preferred form of the invention an anti-sag hinge comprises a flange assembly having a mounting flange, a lower hinge barrel and an upper hinge barrel. The upper hinge barrel is removable mounted to the mounting flange. The hinge also has a strap assembly pivotally coupled to the flange assembly. The strap assembly includes a strap and a cylinder portion removable coupled to the lower hinge barrel and the upper hinge barrel.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front view of an anti-sag hinge embodying principles of the invention in a preferred form.
FIG. 2 is a front view of the anti-sag hinge of FIG. 1, shown with the covers removed.
FIG. 3 is a cross-sectional side view of the anti-sag hinge of FIG. 1.
FIG. 4 is a top view of the anti-sag hinge of FIG. 1.
FIG. 5 is a front view of the anti-sag hinge of FIG. 1, shown with the upper hinge barrel lifted from its mounted position to a removed position.



DETAILED DESCRIPTION
With reference next to the drawings, there is shown an anti-sag hinge 10 according to the present invention. The hinge 10 includes a mounting flange assembly 12 pivotally coupled to a strap assembly 15. It is to be appreciated that the hinge 10 shown in the drawings is configured for use with a walk-in refrigerator or freezer door. The jamb and doors are well-known in the art and need not be disclosed further herein. It is to be further appreciated that the hinge 10, either alone or in combination with another hinge in accordance with the present invention, support a door (not shown) in the usual manner.
The mounting flange assembly 12 includes a mounting flange 16 having four mounting holes 17 therethrough adapted, to receiving unshown mounting bolts or screws, a lower hinge barrel 18 extending from the mounting flange 16, and a removably mated upper hinge barrel 19 extending from the mounting flange 16. The upper and lower hinge barrels provide for a dual or double shear system (two positions wherein a shearing force is provided between the strap assembly and the flange assembly 12) that provides a stable connection between the strap assembly 15 and the flange assembly 12. The lower hinge barrel 18 includes an internally mounted cam 21 which enables the hinge to be a riser type hinge, although this is merely an option of the present invention. The lower hinge barrel 18 also includes a shoulder bolt hole 22 therethrough. The upper hinge barrel 19 includes a dove-tail flange 23 and a shoulder bolt hole 24 therethrough which includes a countersunk hexagonal hole portion 25. The dove-tail flange 23 is configured to removably mate with a tapered slot 26 extending from the top edge of the mounting flange 16. The mounting flange assembly 12 also includes a removable upper flange cover 28 configured to cover the upper hinge barrel 19 and a removable lower flange cover 29 configured to cover the lower hinge barrel 18. The covers 28 and 29 are provided for many reasons, including aesthetics and to meet the sanitary requirements employed in the industry as specified by the National Sanitation Foundation.
The strap assembly 15 includes a strap 31 extending from a cylinder portion 32. The term cylinder portion 32 is meant to describe the enlarged casing located at the end of the strap and the encased bearings, spring, and cam described in more detail hereinafter. The term cylinder portion is not intended to be limited to a cylinder shape, as this portion or parts of this portion may be of many known shapes and are not necessarily cylindrical in shape. The cylindrical portion 32 includes an upper strap bearing 33, a lower strap bearing 34, a thrust washer 35, a spring 36 mounted between the lower strap bearing 34 and the thrust washer 35, and a cam follower 37 configured to mate with cam 21. A shoulder bolt 38 extends through the upper hinge barrel mounting bolt hole 24, the upper strap bearing 33, the thrust washer 35, the spring 36, the lower strap bearing 34, the cam follower 37, the cam 21, and through the lower hinge barrel mounting bolt hole 22. A hex nut 39 is threaded onto the lower end of the shoulder bolt 38 while the head portion 40 of the shoulder bolt is configured to fit snugly within the hexagonal hole portion 25.
The strap 31 includes four elongated mounting holes 42, a screw adjustment flange 43 having a threaded screw hole 44 therein, an end guide 45, an upper guide 46 and a lower guide 47. The strap 31 also includes a moveable adjustment bracket 50 mounted for lateral movement relative to the underlying strap 31. The movement of the adjustment bracket 50 is limited by the end guide 45, upper guide 46 and lower guide 47, which each reside within notches 51 extending inwardly from the peripheral edge of the adjustment bracket 50. The adjustment bracket 50 also includes an adjustment screw mounting flange 52 and an adjustment screw 53 extending through an adjustment bracket mounting hole 54 and threaded into screw adjustment flange screw hole 44. A retaining ring 55 is fitted upon the mounting screw 53 to secure its position. Lastly, the adjustment bracket 50 includes four mounting holes 56 extending therethrough and generally in alignment with strap elongated mounting holes 42. Again, the strap assembly also includes a cover 57 configured to fit snugly over the strap 31 and cylindrical portion 32 to protect and seal the interior of the strap assembly.
In use, the hinge 10 is mounted to the refrigerator or freezer door in the conventional manner as is well known in the art. The mounting flange 16 is secured to the jamb by the use of screws (not shown) that extend through the mounting flange mounting holes 17 and into the jamb. A conventional walk-in refrigerator or freezer door is similarly secured to the hinge 10 by four screws (not shown) that extend through the four mounting holes 17 of the strap assembly adjustment bracket 50 and through the four elongated mounting holes 42 of the strap 31.
Next, the adjustment screw 53 is rotatably threaded into the threaded hole 44 of the screw adjustment flange 43 to cause relative movement between the adjustment bracket 50 and the underlying strap 31. This relative movement causes the movement of the door relative to the stationary jamb, as the elongated holes 42 allow movement of mounting screws and adjustment bracket. The movement of the door enables the door to be properly aligned. The mounting screws are then fully tightened into the door to prevent further movement of the strap. Moreover, should the door sag over time, the mounting screws are slightly loosened and the adjustment screw is merely threaded to once again cause movement of the door to a properly aligned position, as previously described.
To remove the door from the jamb, the covers 28, 29 and 57 are removed. The hex nut 39 is then unthreaded from the shoulder bolt 38 and the shoulder bolt 38 is lifted and removed. Next, the upper hinge barrel 19 is lifted so that the dove-tail flange 23 is slides upwardly and is removed from the tapered slot 26, as shown in FIG. 5. With the upper hinge barrel 19 disengaged from the upper strap bearing 33, the strap assembly 15 may be raised vertically from the flange assembly 12 thereby removing the door from the jamb. As such, it should be understood that the hinge of the present invention has double shear capabilities or construction, yet it is configured to enable one to lift the door from the jamb.
Thus, the present invention fulfills the need in the art for an apparatus and method for providing a double shear hinge that enables a door to be lifted from and removed from a door jamb. This need is fulfilled by providing an anti-sag hinge for commercial walk-in refrigerator or freezer doors that includes a removably upper hinge barrel.
It should be understood that the upper hinge barrel may be designed to be removed from the mounting flange in a number of alternative manners, such as with mounting screws, coupling means, locking means, or other similar types of engagement therebetween.
While this invention has been described in detail with particular reference to the preferred embodiments thereof and the best mode of practicing same, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described herein above and as set forth in the appended claims.

## Claims

1. An anti-sag hinge comprising:
a flange assembly having a mounting flange, a lower hinge barrel and an upper hinge barrel, said lower hinge barrel fixedly mounted to said mounting flange, said upper hinge barrel being removably mounted to said mounting flange and movable relative to said lower hinge barrel, and
a strap assembly pivotally coupled to said flange assembly, removable coupled to said lower hinge barrel fixedly and said upper hinge barrel,
an upper hinge barrel removably mounted to said flange and movable relative to said lower hinge barrel
said upper hinge barrel includes a dovetail flange, and wherein said mounting flange includes a tapered slot configured to mate with said dovetail flange, whereby said upper hinge barrel is removably mounted to said mounting flange.

2. The anti-sag hinge of claim 1 further comprising a bolt extending through said upper hinge barrel, said cylinder portion and said lower hinge barrel.

3. The anti-sag hinge of claim 2 wherein said upper hinge barrel includes a recessed bolt head hole and wherein said bolt includes a bolt head configured to mate with said recessed bolt head hole.

4. An anti-sag hinge for doors being suited for mating engagement with an associated cabinet or jamb, the anti-sag hinge comprising:
a mounting flange adapted to be mounted to the jamb, said mounting flange having a plurality of screw openings there through;
an upper hinge barrel removable mounted to said flange;
a lower hinge barrel mounted to said flange;
a strap assembly adapted to be mounted to the door and pivotally coupled to said mounting flange, said strap assembly having a strap with a plurality of screw openings there through and a cylinder portion removable coupled to said upper hinge barrel,
said upper hinge barrel includes a dovetail flange, and wherein said mounting flange includes a tapered slot configured to mate with said dovetail flange, whereby said upper hinge barrel is removably mounted to said mounting flange.

5. The anti-sag hinge of claim 4 further comprising a bolt extending through said upper hinge barrel, said cylinder portion and said lower hinge barrel.

6. The anti-sag hinge of claim 5 wherein said upper hinge barrel includes a recessed bolt head hole and wherein said bolt includes a bolt head configured to mate with said recessed bolt head hole.