The present invention relates to a beverage dispenser, and, more particularly, to a beverage dispenser for partially frozen beverages with an improved drive and sealing system.
In the food service industry, various machines have been developed to produce, store, and dispense a partially frozen beverage, such as a slush-type beverage. In general, such machines mix water and a flavored component, freeze the mixture, and then dispense a partially frozen beverage product with a slush-like consistency. Such machines are often referred to as “granita” machines.
In general, such a granita machine includes a bowl for storing the beverage product. A freezing cylinder extends through the bowl and houses evaporator coils (of a refrigeration circuit) that cools the beverage product to the desired temperature. The surface of the freezing cylinder is typically metal and is in direct contact with the evaporator coils, resulting in a large and efficient heat exchange surface. Also located within the bowl is an auger which rotates about the freezing cylinder to shave frozen beverage product off of the surface of the freezing cylinder and to circulate the beverage product within the bowl, resulting in the partially frozen or slush-like consistency of the beverage product.
In most prior art constructions, a granita machine includes a drive shaft that extends through the center of the freezing cylinder and is connected to the auger. At the rear of the granita machine, this drive shaft is operably connected to a gear arrangement and motor. For example, as shown in
Furthermore, the gear arrangements in prior art constructions are often prone to field failures as a result of heat stresses and overload. In many cases, relatively small C-frame motors are coupled to a gear box, which, in the context of a granita machine, often results in overloading conditions and excessive heat issues. Such overloading and excessive heat issues can reduce the life of the gears, lubricants, and bearings. For example, excessive heat reduces the lubrication ability of the lubricant internal to the gear arrangement, thus often leading to premature failure. For another example, overloading adds high levels of stress to the gear arrangements, thus resulting in failure of the gear teeth in the gear arrangement. Lastly, to the extent that there is any leakage of the partially frozen beverage product in the vicinity of the gearing arrangement, such leakage can also lead to wear and premature failure of the gear arrangement.
The present invention is a beverage dispenser for partially frozen beverages with an improved drive and sealing system.
In a beverage dispenser made in accordance with the present invention, the beverage dispenser includes one or more bowls. In each bowl, there is a freezing cylinder, and there is a dispenser assembly at the front end of each bowl for dispensing the beverage product. In each bowl, there is also an auger which rotates about each freezing cylinder to shave frozen beverage product off of the surface of the freezing cylinder and to circulate the beverage product within the respective bowls, resulting in the partially frozen or slush-like consistency of the beverage product.
An exemplary auger for use in a beverage dispenser made in accordance with the present invention is preferably a unitary member molded from a thermoplastic material. The auger preferably includes a helical flange (or flight) that is reinforced by first and second longitudinal ribs that extend the length of the auger. At one end, the helical flange terminates in a cylindrical member that defines an internal cavity. The freezing cylinder includes a boss extending from its front surface that is received in the internal cavity defined by the cylindrical member. Thus, once assembled, the position of the auger relative to the freezing cylinder is maintained, in part, by the connection of the cylindrical member of the auger to the boss extending from the front surface of the freezing cylinder; however, the auger is still free to rotate relative to the freezing cylinder.
In each bowl, the auger is driven from the rear, and thus, there is no drive shaft that extends through the freezing cylinder. In this regard, the auger is preferably formed with an integral ring gear at its second end, which, when assembled, is positioned near the rear of the beverage dispenser. The ring gear is engaged by a drive gear, and the drive gear is rotated by a belt and pulley arrangement.
In an exemplary belt and pulley arrangement, a first pulley is mounted to a common shaft with the drive gear. The first pulley is then operably connected to a second pulley by a first belt. The second pulley is mounted on another shaft with a third pulley, such that the second pulley rotates with the third pulley on the shaft. The third pulley is then operably connected to a fourth pulley by a second belt. The fourth pulley is driven by a motor, which, through the belt and pulley arrangement described above, causes the drive gear to drive the ring gear to rotate the auger.
In such a construction, there is no drive shaft that extends through a freezing cylinder, and therefore, there is no shaft seal in the lower front portion of the dispenser, where it would be continuously submerged in the partially frozen beverage product. Accordingly, the beverage dispenser of the present invention eliminates the attendant problems of leakage at a front shaft seal as is common in prior art constructions. Furthermore, replacing prior art gear arrangements with belt and pulley arrangements minimizes the problems of heat generation and allows for the use of larger drive motors to better handle the mixing load, while also reducing maintenance and repair costs. As an additional benefit, cleaning of the components is much easier as compared to prior art constructions as a bowl and associated auger can be readily pulled forward and removed from the dispenser as a complete assembly and taken to a wash area for cleaning.
The present invention is a beverage dispenser for partially frozen beverages with an improved drive and sealing system.
As shown in
Referring now to
Referring now to
Referring still to
In this exemplary embodiment, as a result of the respective ratios described above, each drive gear 62a, 62b is driven and rotates at a speed of 155 RPM when the respective motors 90a, 90b are operating at a speed of 1075 RPM. Furthermore, because there is a gear ratio of 3.5:1 between the respective drive gears 62a, 62b and the ring gears 58a, 58b, the augers 50a, 50b effectively rotate at a speed of 44 RPM.
As mentioned above, in such a construction, there is no drive shaft that extends through the respective freezing cylinders 30a, 30b, and therefore, there is no shaft seal in the lower front portion of the dispenser 20, where it would be continuously submerged in the partially frozen beverage product. Accordingly, the beverage dispenser 20 of the present invention eliminates the attendant problems of leakage at a front shaft seal as is common in prior art constructions.
Furthermore, replacing prior art gear arrangements with belt and pulley arrangements minimizes the problems of heat generation and allows for the use of larger drive motors to better handle the mixing load. Also, maintenance and repair costs are reduced, as most issues with belt and pulley arrangements are more easily resolved as compared to gear arrangements.
As an additional benefit, in such a construction, cleaning of the components is much easier as compared to prior art constructions as each bowl 24a, 24b and each associated auger 50a, 50b can be readily pulled forward and removed from the dispenser as a complete assembly and taken to a wash area for cleaning.
Finally, it should be recognized that an exemplary beverage dispenser made in accordance with the present invention would include a typical cooling system 90 to produce the necessary refrigeration circuit. Specifically, evaporator coils 35 are inside the respective freezing cylinders 30a, 30b (see
One of ordinary skill in the art will also recognize that additional embodiments are possible without departing from the teachings of the present invention. This detailed description, and particularly the specific details of the exemplary embodiment disclosed therein, is given primarily for clarity of understanding, and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit or scope of the invention.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/379,813 filed on Sep. 3, 2010, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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61379813 | Sep 2010 | US |