US 3855732 A
A threshold strip for sliding doors having bearing tracks for supporting and guiding the doors, the tracks being removable and replaceable.
Description (OCR text may contain errors)
Ilite its Sheat Dec. 24, 1974 THRESHOLD STRIP FOR SLIDING DOORS HAVING REPLACEABLE BEARING TRACK  Inventor: James E. Sheaf, Obetz, Ohio  Assignee: Rollyson Aluminum Products,
Sheridan, Ohio 221 Filed: Oct. 15, 1973 21 Appl. No.: 406,142
 US. Cl 49/425, 16/96, 160/201  Int. Cl E05d 13/02  Field of Search 49/425  References Cited UNITED STATES PATENTS 2,788,097 4/1957 Frick 49/425 3,530,618 9/1970 Grossman 49/425 X FOREIGN PATENTS OR APPLICATIONS 263,308 7/1968 Austria 49/425 Primary Examiner-Kenneth Downey Attorney, Agent, or FirmMahoney, Miller & Stebens  ABSTRACT A threshold strip for sliding doors having bearing tracks for supporting and guiding the doors, the tracks being removable and replaceable.
4 Claims, 4 Drawing Figures PATENTEDBEB24|974 3,855,732
sum 10; 2
THRESHOLD STRIP FOR SLIDING DOORS HAVING REPLACEABLE BEARING TRACK BACKGROUND OF THE INVENTION The present invention relates to the threshold strip usually provided for supporting sliding doors. This threshold strip is usually in the form of an aluminum extrusion. It includes one or more upstanding ribs which serve as bearing or supporting tracks for the sliding doors. The doors are usually provided with grooves in the lower edges which fit downwardly over these bearing tracks and are commonly provided with rollers which operate thereon. The tracks are normally made as integral parts of the threshold strip extrusion. When these tracks become worn from use or are damaged, it is necessary to replace the entire threshold strip, which is quite expensive.
SUMMARY OF THE INVENTION The present invention overcomes the necessity of replacing the entire threshold strip upon wear or damage of the bearing track or tracks thereof by providing a track portion which is formed as a separate extrusion and which fits into a groove in the body of the threshold strip. The fit is a frictional fit which effectively holds the track in position but which permits ready removal thereof and replacement.
BRIEF DESCRIPTION OF THE DRAWINGS The best mode contemplated in carrying out this invention is illustrated in the accompanying drawings in which:
FIG. 1 is a perspective view showing sliding doors mounted on a threshold strip formed according to this invention.
FIG. 2 is an enlarged view partly in perspective and partly in section taken substantially along line 2-2 of FIG. 1.
FIG. 3 is a sectional view through the threshold strip showing the bearing track mounted therein.
FIG. 4 is a similar view but showing the track removed from the threshold strip.
DETAILED DESCRIPTION OF THE INVENTION In FIG. ll of the drawings there is illustrated a sliding door unit to which this invention is applicable. This unit consists of the pair of sliding doors l1 and 12 which are slidably mounted in a door frame 13 that includes the threshold strip 10. The threshold strip is formed in accordance with the principles of this invention to include the removable tracks 16 for slidably supporting the respective doors I1 and 12. Each of the doors has a downwardly opening guide groove 18 in its lower edge which fits over the respective track. As indicated in FIG. 2 with respect to the door 11, each of the doors is also usually provided with a plurality of grooved roller units 19 which engage and roll on the respective tracks 16.
The threshold strip 10 is preferably extruded from aluminum but may be extruded from other material or otherwise formed. According to this invention it is provided with an upwardly opening longitudinally extending track-receiving groove 20 which has a curved bottom 21. The track 16 is adapted to cooperate with this groove and is preferably formed with a body extruded from aluminum, or otherwise formed, and a cooperating non-metallic channel 22. The body of the track 16 includes a depending tongue 23 having a curved lower edge 24. The tongue 23 depends below outwardly extending support flanges 25. The upper edge of the body of the track is provided with a bearing rail or rib 26 which is preferably convexly curved transversely. The non-metallic channel 22 is preferably extruded from rigid vinyl although it may be of other non-metallic materials. The tongue 23, with the channel 22 slipped thereon, is adapted to fit snugly into the groove 20 in the threshold strip and to be retained therein by frictional contact. The relative dimensions may be such that the member 22 is slightly compressed upon insertion of the track assembly into the groove. The lower edge of the tongue 23, the bottom side of the channel 22 and the bottom of groove 21 are of complemental transverse curvatures.
When the track assembly is inserted in the groove 20, the supporting flanges 25 will engage the upper flat surfaces 28 of the strip 10 at each side of the groove 20, as indicated in FIG. 3. This will support the weight of the door and prevent undue compression on the nonmetallic channel 22. The supporting portion of the track will project upwardly from the surface 28 so that the transversely curved bearing rail 26 will thereby be located at a level above the surfaces 28 of the threshold strip 10 to receive and support the grooved roller units 19.
Whenever either of the tracks 16 become unduly worn or damaged, it is merely necessary to pull the assembly upwardly from the groove 20 in the threshold strip and replace it with a new assembly. Since the track assembly is a separate unit, it may be removed and replaced at a much lower cost than the replacement of the entire threshold strip 10 as in the prior art. The non-metallic channel 22 which receives the tongue 23 will prevent welding or sticking of the two metal members if they were in direct contact. In fact, the plastic channel 22 actually provides a seal between the tongue and groove to prevent entrance of moisture or dirt.
Having thus described the invention, what is claimed 1. A threshold strip for supporting a sliding door comprising a longitudinally extending body with side edges having a longitudinally extending upwardlyopening track-receiving groove formed therein intermediate the side edges, a track removably mounted on said body, a longitudinally extending depending tongue on said track so shaped relative to the groove that it can be slipped downwardly into the groove to be retained therein by friction or be withdrawn upwardly out of the groove for removal, a longitudinally extending support portion on said track above said tongue with a longitudinally extending bearing surface at its upper edge, in which the groove is of substantially U-form in transverse cross-section and the depending tongue is of cooperating similar cross-section so that it can be slipped downwardly into the groove or be pulled upwardly therefrom, and including longitudinally extending support flanges on the track at a level between the depending tongue and the support portion and extending laterally outwardly in opposite directions to provide support surfaces which rest on the strip body at opposite sides of the groove therein.
2. A threshold strip according to claim 1 in which said threshold strip and track are both of metal and in which said flanges have their support surfaces located at a selected level so that the lower edge of the tongue will not contact with the bottom of the groove when said support surfaces engage the body and said tongue being of a width less than that of the groove to provide a U-shape space between the tongue and the groove, and a non-metallic channel member in said U-shape space fitting upwardly around the depending tongue beneath said support flanges and engaging the sides and bottom of the groove.
3. A threshold strip according to claim 2 in which the removable track is a metal extrusion with the support