BACKGROUND
Various basket lifting mechanisms have been provided in deep fat fryers. A forward lower portion mounting of lifting mechanism at fryer casing was invented by Anetsberger et al. (U.S. Pat. No. 4,508,026). Further advancements were made by Prudhomme, U.S. Pat. No 5,469,778) for large quantities of food in larger fryers vertically reciprocated along a guide track. Baillieul et al. invented electric deep fat fryer comprising a vat, cooking bath, an electric heater (U.S. Pat. No 6,138,552). Savage (U.S. Pat. No. 6,588,325) filed a patent on a mechanical assist for raising and lowering food baskets in a deep fat fryer.
ADVANTAGES OF CURRENT INVENTION
So far, the earlier lifts for fryers are built-in models. Compared with the earlier lifting mechanisms for deep fryers, the current invention is unique because it is a stand-alone unit. The unit has two independent lifts with two lifting arms suitable for lifting two baskets independently. The unit has a small dimension of about two inches in thickness, with height and width suitable for installation in several locations by the fryer or inside the fryer. It has two digital timers to control the two lifts independently. The user can easily change the predetermined time. The system is stable; it will stop safely when the electric power is accidentally cut off and it will reset to a standby position when the power is recovered. It is built to lift food load as heavy as needed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the structure of two lifts in a mechanical unit.
FIG. 2 shows the structure of the linear motion assembly.
FIG. 3 shows the structure of the spring coupler 11, balancing spring 10, linear bearing set 8 and the magnet sealing set 20.
FIG. 4 is a front view of the side-installation model and its installation at the side of the fryer. One new arm sets 22, 23 for this model has been invented.
FIG. 5 is a front view of the back-installation model and its installation at the back of the fryer. One new arm sets 24, 25 for this model has been invented.
FIG. 6 is a front view of the top-installation model and its installation at the top of the fryer. One new arm sets 26 for this model has been invented.
DETAILED DESCRIPTION
The mechanical unit has two independent lifts controlled by two timers 21. The mechanical parts of the two lifts are mounted in a steel case 19 as shown in FIG. 1. Each lift is composed of a linear motion assembly 1˜13, rotation limiting plates 14,16, position limiting switches 17, a balancing spring 10, and a magnet sealing set 20. The details of the linear motion assembly are shown in FIG. 2. The motor 13 provides the drive for the linear motion when it receives a signal from the timer and the relay circuit. The motor is connected to the screw rod 6 by a spring coupler 11. The screw rod is installed in a steel tube 2 using two rotational bearings 5. The steel tube 2 is welded on plates 12. A slider 7 mounted on the screw rod will move up and down as the motor rotates in a clockwise/counter-clockwise direction. This linear motion is connected to tube 1 by a pin 9 through to rectangular opening on tube 2. The bearings 3 and 4 are mounted on tube 2 and provide the support between tube 1 and tube 2. The four bearings mounted on tube 8 at 90 degrees angle from each other are named linear bearing set which provides the supporting structure at the lower end of tube 1. The tube 8 is fixed on tube 1 by 4 screws. The same linear bearing set of larger size 20 is mounted on the top of the case to provide guidance and reduce friction of tube 1 with the case.
FIG. 3 shows the details of the spring coupler 11, balancing spring 10, linear bearing set 8 and magnet sealing set 20. The spring coupler has both ends bent. A notch is opened at the ends of the screw rod and the shaft of the motor. These notches allow the spring coupler to be mounted on the ends of the screw rod and the shaft of the motor. The advantages of such spring couplers are that it is easy to make, has a low cost and can self lock. Once mounted, it will never come loose due to extended use.
The balancing spring 10 is a varying diameter spring. It can be compressed to a height half of constant diameter spring with the same number of turns.
The linear bearing set 8 has four bearings welded on the steel tube 8. It features a high load capability, low friction.
The magnet sealing set 20 is composed of four half-ring magnets and two pieces of half-ring rubber. The whole set can be easily removed from the unit for cleaning.
The side-installation model is shown in FIG. 4. The positions of the arm components 22,23 can be adjusted by loosening the screws, and then sliding.
The back-installation model is shown in FIG. 5. The positions of the arm components 24,25 can be adjusted by loosening the screws, and then sliding.
The upper-installation model is shown in FIG. 6. The positions of the arm components 26 can be adjusted by loosening the screws, and then sliding.
REFERENCES
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4,508,026
April 1985
Anetsberger et al.
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5,469,778
November 1995
Prudhomme et al.
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6,138,552
October 2000
Baillieul et al.
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6,588,325
July 2003
Savage
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7,255,379
June 2004
Adams
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