Patent Application
20140182476
The present invention relates to overhead conveyors, which typically comprise at least an “I-beam” track 1, trolleys 2 which have opposed wheels 3 engaging the bottom flanges of said I-beam track 1 on opposite sides of the center web of the beam, and a driven conveyor chain (not shown) connected to said trolleys at spaced intervals (
While power trolleys are sometimes used directly to convey whatever items are being processed, they are more typically used to drive free trolleys 10, which travel freely on paired, laterally spaced load wheels 20 running on the lower flanges 41 of spaced inwardly facing “C” shaped tracks 40. Two horizontally oriented guide wheels 30 at the bottom of each free trolley are positioned between the C channel flanges 41, to help keep trolley 10 from shifting too far to the right or left as they travel in tracks 40.
The C channel tracks are supported by a pair of support arms 5, mounted atop the I-beam 1 and depending downwardly past either side thereof and past either side of the power trolleys. Downwardly depending pushers (not shown) are mounted on either the power trolleys 1 or the chain carried by and driving the power trolleys, for engaging dogs 11 on the free trolleys, to thereby move the free trolleys 10 along in their tracks 40. When it is desired to stop a trolley, mechanisms are provided for retracting either the pushers or the dogs 11, so that the trolley stops. The so called free trolleys thus carry the heavy loads which are to be moved from place to place. The trolley and “C” track arrangement can be used as powered trolleys driven by a drive chain. However, this arrangement is typically used as a set of free trolleys.
In accordance with long standing industry practice, trolleys are numbered in accordance with the approximate height of the I-beam or C channel tracks they are carried on. Industry standards, and longstanding industry practice call for 3 inch tracks, 4 inch tracks and 6 inch tracks. Thus, there have long been 3 inch trolleys, 4 inch trolleys and 6 inch trolleys.
Also by long recognized industry standards, the so called free trolleys (which can be driven) are built to carry heavier loads than the so-called driven trolleys. The free trolleys come in a standard grade and a heavier grade for carrying heavier loads. These loads are in accordance with long recognized standards. Thus the heavy load capacities for 3, 4 and 6 inch free trolleys are:
The present invention comprises an overhead conveyor, components therefor and method for making same, in which the conveyor trolley is designed for a channel having a height “X,” but is built with a maximum allowable load value which is equal to or greater than the maximum allowable load value for a trolley used in channels of height greater than X. The trolley of the present invention utilizes load wheels having double row bearings.
This surprising departure from industry standards makes it possible to use, for example, four inch trolleys and four inch tracks, to care a load normally requiring six inch trolleys and six inch tracks.
Trolleys 10a of the preferred embodiment comprises a pair of spaced side plates 50a joined by bolts 51a (
Instead of a single row of bearing wheels conventionally used in conveyor trolleys, load wheels 20a have a doable row of bearings 22a and 22b, positioned next to and parallel to one another within the confines of wheel 20a (
As can be seen by comparing the prior art trolley of
The trolley wheels 22a of the preferred embodiment are also preferably from 5 to 20%, more preferably from 10 to 15% less in mean outside diameter than the standard 2.4 inch diameter wheels used on 3 inch trolleys (i.e. 1.9-2.3, preferably 2.0-2.2 inches instead of 2.4), and the standard 3.2-3.3 inch diameter wheels used on the 4 inch (i.e. 2.5-3.0, preferably 2.7-2.9 inches) and the standard 4.0-5.25 inch wheels used on 6 inch trolleys (i.e. 3.2-3.8 inches, preferably 3.4-3.6 inches). The use of smaller outside diameter wheels is surprisingly made possible by the use of double row bearings. The decreased size of the load wheel allows for the use of smaller C-channels, saving significant materials.
The trolley guide wheels 30a also preferably employ a double row of bearings 32a and b, which significantly increase the overall load capacity of the wheel. (
Each wheel 30a is formed on it interior to define an inwardly opening proximate outer race 31a and an outwardly opening distal outer race 31b, separated by a shared outer race wall 31c. A proximate inner race defining ring 33a and a distal inner race defining ring 33b are inserted into wheel 30a from opposite sides, so as to abut one another and trap the bearings 32a between the inner races 33a and b, and the outer races, 31a and b, respectively, inner race rings 33a and b are carried on hub 37, which includes an inside lip 37a, which locks proximate inner race 33a in place when the components are assembled. A similar outer lip bob is then swaged on the outside edge of hub 37 to lock distal inner ring 33b in place.
The two substantially parallel side-plates 50a are connected preferably by at least grade 8 bolts 51a, rather than by grade 5 bolts as are conventionally uses. These plates are preferably at least 15% thicker than prior art ⅜ inch thick trolley side-plates, and more preferably, at least 25% greater ( 7/16 to ½ of an inch).
In a preferred embodiment, the channel strengths as determined by pounds of material per foot of track, are 50-75% greater than standard strengths.
The benefits of the present invention have not at ail been recognized or thought of by prior artisans. The use of at least double-row bearings in the load and guide wheels significantly increases the load capacity of the trolley without increasing the size of the trolley or track. This allows, for instance, loads traditionally carried only by a 6-inch trolley on a 6-inch track to be carried on a 4-inch track and trolley. Further reduction to the amount of materials needed for tracks is achieved by reducing the axial height of the load wheels.
For example, one 4 inch trolley has been load tested to 23,800 pounds without breakage. The preferred embodiment trolleys can he comfortably rated to twice the standard loads given for prior art trolleys of the same size:
Other embodiments of the invention are contemplated by the inventor.
The present application claims priority to U.S. Provisional application Ser. No. 61/747,172, filed Dec. 28, 2012, entitled HIGH CAPACITY CONVEYOR TROLLEY AND METHOD, and U.S. Provisional application Ser. No. 61/764,774, filed Feb. 14, 2013, entitled HIGH CAPACITY CONVEYOR TROLLEY AND METHOD.
| Number | Date | Country | |
|---|---|---|---|
| 61764774 | Feb 2013 | US | |
| 61747172 | Dec 2012 | US |
