Patent Application
20070101653
The invention relates to an improved casement window, and in particular to a casement window hinge assembly having structure to reduce sash sag.
Casement windows assemblies are well known in the art and described in, for example, U.S. Pat. No. 3,845,585 to Cecil, entitled “Casement Window,” and U.S. Pat. No. 4,254,583 to Smits et al., entitled “Window Unit,” which are both hereby incorporated by reference herein. In general, a casement window includes a window sash comprised of a sheet of glass surrounded by wood, vinyl or metal structure. A casement window has the sash hinged to one side in comparison to windows where the sash slides within the frame. The window sash engages the window frame though an upper and lower hinge assembly. The casement window sash swings on a hinge within the window frame along a vertical axis. Typically a crank mechanism is attached to the lower hinge for selectively opening and closing the window sash. Proper performance of the casement window requires that the window sash be properly aligned within the window frame.
One of the more common issues regarding casement windows is sash sag, which occurs when the sash portion of the window is out of square with the window frame. Sash sag can result from movement during installation, improper hinge positioning by the window manufacturer, settling of the building, warpage of the window or from external contact with the window sash in the open position. A window with sash sag will not properly seal. As a result the window is less effective in preventing moisture from coming in to the structure as well as increasing energy costs for heating and cooling of the building. Moreover, the improper seal may allow moisture into the window frame itself, which can lead to rotting of the window frame and the structure.
Correction of sash sag requires realigning the hinge so that the sash sits properly within the window frame. On some windows this requires disassembly of the hinge, which is labor intensive and costly. In the alternative, sash sag may be corrected with an adjustable hinge mechanism. An example of an adjustable mechanism designed to alleviate sash sag is disclosed in U.S. Patent Re. 34,657 ('657 reissue) to La See, entitled “Cam Adjustment Device For Casement Window Unit,” which is hereby incorporated by reference herein. More specifically, the '657 reissue discloses an index cam comprising a series of serrations that can engage a plurality of serrations on the track of the hinge assembly, which permits the cam to move relative to the track and facilitates adjustment of a link connected to a casement window sash. However, the engagement of the serrations on the cam with corresponding serrations on the track only permits predetermined, or defined, movements of the cam within the track. Additionally, the detailed structure of the cam and the track can increase manufacturing costs and make it make difficult to adjust the window sash once the hinge assembly has been installed.
With the number of residential casement windows being installed in new and existing homes, it would be desirable to provide a hinge assembly that can reduce or eliminate sash sag and overcome the limitations mentioned above. What is still needed is an adjustable hinge assembly that can be easily adjusted without disassembly of the casement window to reduce and/or eliminate sash sag, and that can be manufactured at a lower cost relative to existing hinge assemblies.
The hinge assembly of the present invention addresses the above-mentioned needs by providing a mechanism that can be adjusted to compensate for sash sag without requiring disassembly of the casement window assembly. Additionally, the hinge assemblies of the present disclosure do not comprise locking structures and therefore can be manufactured at lower costs relative to existing hinges.
In a first embodiment, the improved hinge assembly includes a track having an upwardly struck cam engaging portion defining a tri-lobular aperture, a first elongated arm or sash arm pivotably coupled to a slide on the track assembly, and a second elongated arm or support arm pivotably coupled to the track assembly and to the first elongated arm. The improved hinge further includes a cam member operably coupling the second elongated arm and the track. The cam member has a bi-lobular cam portion adapted to engage the cam engaging structure of the track such that the cam portion is selectively shiftable within the cam engaging structure. Shifting the cam portion within the cam engaging structure facilitates positional adjustment of the second elongated arm, and the attached window sash, which can reduce and/or eliminate sash sag. The cam engaging structure can be a tri-lobed aperture, while the cam portion can comprise an oval shape, an elliptical shape or the like. In embodiments where the aperture engaging portion is a bi-lobular, generally oval shaped cam, the cam portion can allow the cam member to be shifted up to about thirty-five degrees longitudinally in either direction from a center position within the tri-lobular aperture.
Due to the structure of the cam engaging structure and the cam portion, the second elongated arm and the attached window sash can be adjusted relative to the track such that sash sag can be reduced and/or eliminated. In some embodiments, the cam portion is biased against the track with a retainer, thereby creating friction for resisting movement of the cam portion within the cam engaging structure. This friction enables the adjustable cam to maintain position without the use of locking structures such as protrusions, serrations or the like, which in turn enables finer adjustment of the second elongated arm. Moreover, since the cam portion and the cam engaging structure do not comprise locking structures such as protrusions or serrations, the hinges of the present disclosure can be manufactured at a lower cost than hinges having locking structures and the like. The structure of the cam portion, along with the cam engaging structure, can also facilitate adjustment of the second elongated arm, and the attached window sash, without disassembling the sash from the hinge assembly.
In a first aspect, the invention pertains to a hinge for use with casement window assemblies having a track with a cam engaging portion defining a tri-lobed aperture, a first elongated arm pivotably coupled to a slide on the track, and a second elongated arm pivotably coupled to the track and to the first elongated arm. In these embodiments, the cam member is operably coupled to the second elongated arm and has an oval bi-lobular engaging portion positioned within the tri-lobed aperture, wherein the oval engaging portion is selectively shiftable in the tri-lobed aperture.
In a second aspect, the invention pertains to a cam for use in a hinge assembly, the cam including a body portion having a first end and a second end, an oval engaging portion oriented towards the first end, and a link engaging stud portion oriented towards the second end. In these embodiments, the oval engaging portion can be adapted to engage with and move within a corresponding aperture in a track such that the cam member can be selectively shifted up to about thirty-five degrees longitudinally in either direction from a center position within the aperture.
In a third aspect, the invention pertains to a method of reducing sash sag, the method including adjusting an elongated arm connected to a cam member having an oval engaging portion, wherein the oval engaging portion is positioned within a tri-lobed aperture of a track.
a is a side view of an embodiment of a cam member having a bullet shaped engagement portion;
b is a top view of the cam member of
c is a bottom view of the cam member of
a is a plan view of an alternate embodiment of a hinge assembly according to the invention;
b is an enlarged view of a portion of the plan view of
c is a perspective view of the cam member of
d is a plan view of the cam member of
e is a plan view of the cam member of
f is a cross sectional view of the cam member and track taken along section 10f-10f of
The present invention is an adjustable cam unit disposed within a casement window hinge for alleviating sash sag. As depicted in
Upper and lower hinge assemblies 20a, 20b, which facilitate hingably mounting the window sash 15 to the window frame 11. The hinge assemblies 20a, 20b generally include a track 22 mounted to the window frame 11, a sash arm 23 coupled to the window sash 15 with one end longitudinally slidable on track 22, and a support arm 24 pivotally coupled on a first end to track 22 and to sash arm 23 at the opposing end. In operation, window sash 15 pivots in and out of frame 11 on hinge assemblies 20a, 20b by rotating crank mechanism 26. While the present description generally refers to casement windows, the present invention could be used with other types of window hinges including awning style windows.
Referring to
Track 22 is operably connected to sash arm 23 through a slide block 27. Slide block 27 includes a pivotable connection 28 to sash arm 23 that allows for rotation of the sash arm 23 about the vertical axis. Slide block 27 is longitudinally slidable on track 22 so that the sash arm connection 28 may move longitudinally along track 22. Track 22 is also operably connected to support arm 24 through adjustable cam 29 that enables rotation about the vertical axis as well as selective longitudinal movement. Opposing end of support arm 24 is mounted to a pivotable intermediate link 30 of sash arm 24 that allows for rotation about a vertical axis.
As depicted in
As depicted in
Aperture engaging portion 39 generally includes post 43 and cam 44, both of which are substantially concentric with respect to axis B-B. In an embodiment of the invention, cam 44 may be generally oval shaped as depicted in
Retainer 29b is received on post 43 so as to retain adjustable cam 29 within aperture 32 on track 22. In an embodiment, retainer 29b may be a metal ring interference fit onto post 43 so as to clamp track 22 between retainer 29b and guide plate portion 42. In other embodiments, retainer 29b may be an O-ring, split ring, or the like, made from metal, plastic, rubber or combinations thereof. Retainer 29b and post 43 are received in pocket 35 so that track 22 may be mounted flush to window frame 15.
The operation of adjustable cam 29 is depicted in
Referring to
An alternative embodiment is depicted in
Aperture engaging portion 139 generally includes post 143 and cam 144, both of which are substantially concentric with respect to axis B-B. Cam 144 has a pair of opposing lobes 150, each presenting opposing aperture contact surfaces 152. As depicted, aperture contact surfaces 152 may be slightly concave between post 143 and lobe ends 154. Cam 144 and aperture 132 are coordinatingly dimensioned so that cam 144 is rotatably shiftable in aperture 132 about the vertical axis denoted C-C in the figures.
Retainer 129b is received on post 143 so as to retain adjustable cam 129 within aperture 132 on track 122 as before. Again, retainer 129b may be a metal ring interference fit onto post 143 so as to clamp track 22 between retainer 129b and guide plate portion 142. In other embodiments, retainer 129b may be an O-ring, split ring, or the like, made from metal, plastic, rubber or combinations thereof. Retainer 129b and post 143 are received in pocket 35 so that track 22 may be mounted flush to window frame 15.
In some embodiments, post 143 may have a generally cylindrical portion 145 and may be chamfered at end 137 to form a generally frusto-conical end on post 143. Cam portion 144 is disposed between post 143 and arm support portion 142. Cam portion 144 is sized to allow for movement about the vertical axis within aperture 132.
The assembled configuration and operation of adjustable cam 129 is depicted in
Referring to
The embodiments above are intended to be illustrative and not limiting. One of ordinary skill in the art will recognize that the above description is only one type of hinge assembly, and that the cam and track structures described below can be used with other types of hinges such as, for example, hinges where the sash arm has a fixed pivot axis relative to the track and the support arm is pivotably coupled to a moveable shoe. Although the present invention has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
