Roller grill bearing apparatus

A roller grill bearing assembly that can be adapted to fit on any size roller grill or roller tubes. The bearing assembly substantially increases the bearing land on the roller grill housing and increases the bearing area over the land. The bearing assembly permits the bearing apparatus to be snapped in place on the stamped opening on a sheet metal side panel as done using current manufacturing methods. Further, the bearing assembly can be produced using current manufacturing techniques without significantly changing the cost of production. Most importantly, the invention substantially increases the life span of the bearing.

FIELD OF THE INVENTION

This invention relates to commercial cooking equipment, in particular, a bearing assembly for a roller grill for cooking hot dogs, bratwursts, sausages, and other food products having an elongated shape.

BACKGROUND OF THE INVENTION

The use of a roller grill to cook hot dogs dates back at least as early as 1939. At that time, Dumas, in U.S. Pat. No. 2,185,979, recognized the advantage of using a plurality of rollers to quickly and uniformly cook hot dogs or other similarly shaped foods. Since that time, the roller grill has been associated with America's food icon, the hot dog.

There have been numerous improvements to this device over the years where it has become a part of most commercial food service establishments, which serve large quantities of hot dogs or similarly shaped foods. Manufactures of such units spend a great of time and effort to instruct the purchasers and the equipment operators concerning safety and proper cleaning procedures. The roller grill has a plurality of cooking tubes that rotate by a drive mechanism with each roller tube anchored between opposing sides of the side panels. Each roller tube is fitted with a bearing so that it may turn freely. The present construction of this bearing mechanism is a plastic bearing that is snapped into an opening provided in a sheet metal panel. Cleaning instructions inform the operator to carefully clean each tube so that grease and particles do not get into the bearing that will substantially reduce the bearing's lifespan. Cleaning and the grease seals help prevent grease and debris from entering into the bearings and the drive mechanism which is the major source of early drive failure.

Further, operators are cautioned against using one or more roller tubes as “handles” for moving the grill or placing unusually heavy objects on the grill for storage when the grill is not in use. Present roller grill bearing surfaces are made from relatively soft plastic such as TEFLON polymer that can be easily cut by the sharp edges of the sheet metal opening if the bearing is forced out of alignment due to excessive force or accumulation of grease or dirt. TEFLON is the registered trademark of E.I. Du Pont, Wilmington, Del. for its polytetrafluoroethylene polymer.

There is not found in the prior art a roller grill bearing apparatus that substantially increases the surface area of the bearing, ensures that the bearing will not rotate when snapped in place; can concentrate the friction surface to a known location for better control of wearing, and, yet, can be easily manufactured and installed in a manner similar to present manufacturing techniques.

SUMMARY OF THE INVENTION

It is an aspect of the invention to provide a roller grill bearing assembly that can be adapted to fit on any size roller grill or roller tubes.

Another aspect of the invention is to provide a roller grill bearing assembly that substantially increases the bearing land on the roller grill housing and increases the bearing area over the land.

Still another aspect of the invention is to provide a roller grill bearing assembly that permits the bearing apparatus to be snapped in place on the stamped opening on a sheet metal side panel as done using current manufacturing methods.

Another aspect of the invention is to provide a roller grill bearing assembly that can be produced using current manufacturing techniques without significantly changing the cost of production.

Finally, it is an aspect of the invention to provide a roller grill bearing assembly that increases the life span of the bearing.

DETAILED DESCRIPTION OF THE INVENTION

In order to better appreciate the merits of the invention, a more detailed understanding of the prior art will be undertaken. Referring now toFIGS. 1-5, a typical roller grill bearing is described. This bearing is usually made from bar stock and then machined to provide bearing11. The bearing material is typically TEFLON polymer and/or filled TEFLON polymer. The left side13of bearing11is smaller than the right side15so that channel19is formed in which the sheet metal16of the side wall12will fit into. A hole is punched into the side wall12that corresponds to the diameter of the bearing. Typically, this hole is punched with a CNC fabricator. Anti-rotation lance21is made at the same time. Bearing land17typically ranges from (1.27 millimeters to 1.397 millimeters) 0.050 inches to 0.055 inches wide. Note that bearing notch31is provided such that once bearing11is snapped into place in the hole that has been punched in the sheet metal (SeeFIG. 11), bearing notch31is engaged by lance21to prevent bearing11from turning relative to roller14. Grease seal32is provided to help keep the grease and food particles from entering bearing11. Grease seal32is presently made from TEFLON polymer that is machined from a bar. The seal32is placed on a seal stretcher (not shown) and then allowed to shrink back to roller tube14diameter to seal tube14and bearing11from grease and food debris.

Since roller grills used commercially are subjected to particularly rough treatment such as picking the grill up by tubes14, bearings11experience substantial adverse treatment. A typical life span of current bearings11is about five years but failures have occurred as early as 30 days due to improper handling. Sheet metal16is sharp and can cut through the relatively soft prior art bearing11rather quickly if tubes14are encountering additional stresses with improper handling as discussed above. Therefore, the inventors recognized that to improve the life span of roller grill bearings, since it was not possible to reduce the rough handling of typical users, it would be necessary to increase the bearing land size and eliminate cutting of the bearings due to sharp edge of sheet metal16.

As shown inFIGS. 6 through 13, bearing10provides a substantially greater width for land33. Bearing land33now typically ranges from (3.556 millimeters to 4.064 millimeters) 0.140 inches to 0.160 inches. Also, sheet metal16is punched with a special die to cause the edge of sheet metal16to bend slightly inward as shown inFIG. 10. In this manner, the punched wall of sheet metal16fits on bearing land33as land33has a radius as shown inFIG. 6that corresponds to the die cut edge of sheet metal16such that a sharp edge will not penetrate bearing10.

The left side of bearing10is side20and the right side of bearing10is side22. As with the prior art bearing, bearing10can be snapped into its' opening by hand. Notch24is provided to prevent bearing10from turning relative to roller tube14. With invention10, end housing tab28(SeeFIG. 10) fits into notch24.

As with the prior art bearing11, grease seal32is provided to protect bearing10from grease and food debris.

With these improvements, it is expected that the life span of bearing10will be substantially greater, perhaps double or triple than that of prior art bearings. Also, it is expected that failures from improper handling be can substantially reduced as well.

Although the present invention has been described with reference to certain preferred embodiments thereof, other versions are readily apparent to those of ordinary skill in the preferred embodiments contained herein.