Patent Application
20230375243
A conventional icemaker and dispenser of the type that dispenses ice through an opening in the front of a home refrigerator-freezer is an extremely noisy, unreliable, and annoying device. It typically makes a batch of ice chunks by flowing water into a multi-cavity mold and then it noisily dumps them into a bin. If the mold is slightly overfilled as often happens, the chunks will be frozen together into a clump. As a result of temperature variations due to door openings or automatic defrost cycles, while sitting in the bin, the ice may further conglomerate into a large mass which must be broken apart before being dispensed.
A motorized auger is typically used to pull the ice forward where a whirling rotary hammer noisily smashes the ice apart into dispensable-sized pieces and propels them out a chute at disturbingly high velocity with enough force to smash delicate glassware. When a user inserts a container into the dispenser, the number, shape, and size of ice pieces coming out the chute at any given time is totally unpredictable, so the ice may overfill the container, or it may cause an ice jam and clog the chute. If that happens, the dispenser may keep running but no ice comes out of the chute. When the freezer door is opened, a huge pile of ice may fall out onto the floor. In some designs, an ice jam can push back on the dispenser actuator causing the dispenser to not shut off when the container is removed. If it is then switched over from ice to water, water will pour out and not shut off until the jam is cleared.
The entire system may take up well over a cubic foot of space inside the freezer section of the refrigerator. These systems are often unreliable and if some part of the unit fails, it may take considerable skill, tools, and time to repair the unit in place or to remove it and replace it.
The invention disclosed herein employs a completely different method of producing and dispensing ice that eliminates most of the noise and gently dispenses uniform pieces of ice at predictable intervals.
A large array of single cavity molds is carried along a serpentine path by a belt or chain inside a rectangular housing. The molds move whenever a user requests ice by inserting a container into the dispenser. As a frozen mold reaches the front of the system the ice contained therein is quietly ejected from the mold and gently slides down a chute into the container. When the empty mold moves forward it is refilled with water and gradually freezes as it moves along the serpentine path. A user adjustable speed control could determine how rapidly the ice is dispensed.
Since each piece of ice is contained in its own mold until it is dispensed, it cannot get stuck to any other piece. Thus, no noisy auger or rotary hammer is needed.
It should be noted that these are simplified drawings to illustrate the basic concepts. While they depict a proposed arrangement of the claimed elements, engineering and testing may lead to a somewhat different embodiment to improve performance, manufacturability, cost, etc.
A typical mold 104a on the left side would be fully frozen, while a mold on the right 104b would be freshly refilled with water and may not be frozen. If a large amount of ice is used in a short time, all the fully frozen ice could all get used up, and unfrozen or partially frozen molds could reach the ejection area. A fully frozen mold will be cooled close to zero degrees, but any mold that still contains liquid water will be close to 32 degrees. A temperature sensor (not shown) along the left side near the front would measure the temperature of each mold as it moves forward and would send a signal to the control system to prevent an unfrozen mold from reaching the front and causing a spill. When a frozen mold 106 reaches the front, a specially formed guide wall under the mold (not shown) tilts the mold sideways. Another specially formed guide wall 105 gently pushes forward on the bottom of the tilted molds to push the ice 108, 109 out of the mold and into a discharge chute mounted in the freezer door.
Instead of a passive guide wall to eject the ice, it may be preferable or even necessary to use active means such as a cam or lever to push the ice out more forcefully. A cam or lever could be driven by the transport mechanism to keep it synchronized with the motion of the molds.
It may be possible to simplify the process somewhat by not tilting the molds. In the simplified embodiment the molds stay vertical, and the bottom of the mold is pushed upward ejecting the ice out the top. A guide above the mold causes the ice to tip forward and fall into the discharge chute. However, that method might require too much additional height.
After ice is ejected from a mold 109, the mold drops back to its vertical orientation to be refilled. If only a single mold is being refilled, there is plenty of time to do it. However, if multiple molds are being emptied and refilled in quick succession while the transport mechanism may be running continuously, fill time is severely limited, and needs to be precisely timed to avoid dispensing water between the moving molds. Yet, if the mold is filled too fast, water may splash out. Thus, it may be necessary to have multiple valves and fill nozzles whereby each one fills a mold part way full as it goes by. Three fill valves and nozzles 110 are shown but more or fewer may be needed.
Depending on the size of the refrigerator-freezer, the size and shape of the icemaker and the number of molds contained therein may be different.
Both sides of the belt or chain must alternately engage the pulleys or sprockets as it winds back and forth around them, so the hangers must be attached in a way that does not interfere. The spacing between the hangers should be an exact multiple of space between the teeth of the pulleys or sprockets.
The transport mechanism is mounted to the upper surface of a rectangular horizontal plate. A serpentine slot runs through the plate directly below the transport to provide a way for the hangers to extend down below the plate and connect to the ice molds and move them along under the transport. The continuous slot separates the plate into two pieces, and greatly weakens them both. A top cover is attached to the plate, bridging across the slot in multiple locations to strengthen the plate and to join the two parts together. The top cover also protects the transport mechanism from interference or contamination and provides operator safety. The curves near the front 203 may not be circular, so a fixed guide or a series of small idler wheels may be used to establish the shape of the desired curve. Springs may be employed to maintain suitable tension in the transport.
The individual ice molds would be formed from a durable material that remains flexible at cold temperatures such as silicone rubber, with a more rigid collar at the top where it attaches to the hanger. For simplicity, in most of the drawings the shape of each mold is shown as a plain cylinder. In practice, the molds would have to be wider at the top to facilitate ejection of the ice and will likely be made more squarish which would increase the packing density by about 20%. Because the sidewalls of the molds are tapered, ice is easily ejected from the mold by pushing up on the flexible bottom. For dispensing, the bottom of the mold may be tilted backward to a horizontal orientation so that the ejected ice is directed forward toward the front door of the freezer and into a dispensing chute. Ideally, the resilient mold material would spring back on its own to its original shape after the ice is ejected. If it fails spring back fully, water might overflow when the mold is refilled. To make sure this does not happen, a steel spring could be incorporated into each mold, or other means could be employed to force the mold back to its original shape. For example, a disk could be attached to the bottom of each mold and an angled slotted plate could intercept the disk after the ice is ejected and tug on the mold as it moves along to pull it back to its fully extended shape.
Because water expands by about 9% as it freezes, it would tend to cause the sides of the mold to bulge out, making ejection difficult. Careful design of the mold shape would prevent this problem by allowing the ice to slide upwards in the mold to accommodate the expansion. Another way to prevent side bulge would be to force the bottom to freeze first with the top freezing last. This can be accomplished by having a gentle heater on the underside of the horizontal plate. This would also prevent frost buildup from the liquid water evaporating and condensing on a cold plate. Forcing the molds to freeze from the bottom up may also cause the ice to be clearer due to less entrapped air. Clear ice is considered preferable for cocktails. Carefully directed cold airflow at the bottom of the molds could also help the process.
The belt or chain is moved along its path by a small motor that drives at least one of the pullies or sprockets. The motor starts and stops gently to avoid spilling water from the molds. The motor would most likely be mounted to the horizontal plate.
To simplify wiring, the ice maker may be plugged directly into a mating connector on the freezer door using a flexible ribbon cable. This reduces cost and complexity by avoiding the messy labor-intensive process of running the wires through a hollow door hinge.
In operation, it would be possible to get a single ice cube if desired. The transport would start up and move forward the distance of one mold and stop again. As the ice dropped down the chute, the previously emptied mold would get refilled. In this mode, it could dispense about one cube per second. If many cubes are needed quickly, the transport could run continuously, dispensing about two or possibly three cubes per second. Thus, the entire array of 180 cubes (weighing about 5 pounds) could be dispensed in 90 or perhaps 60 seconds.
Because this quiet icemaker is only about three inches high, two of them could be installed one above the other in a freezer and would still take up less space than a single old-style icemaker. It could even be purchased and installed later by the customer.
When the transport is running in continuous mode, the water filling the molds must turn on and off rapidly to avoid spilling water between the molds. With a single filling spout, each mold may only be in position for less than a half or even a third of a second, which may not be enough time for a complete fill. Thus, multiple filling spouts may be needed with each one doing a partial fill. While it might be possible to use mechanical valves driven by the transport mechanism, solenoid valves under microprocessor control would provide greater flexibility and precision. Some type of non-contact level sensor, perhaps ultrasonic, may be used to provide optimum or even variable fill level.
As with other icemakers built into refrigerator-freezers, a dispenser and operator control panel would be mounted in the freezer door, and the dispenser would also provide water. Crushed ice would be an option, with crushing means mounted within the dispensing chute. A pair of high-torque slow-turning rollers would gently crush each ice cube as it passed down the chute, again making a lot less noise than a conventional crusher.
