Abstract: Diamond bur A has base metal 1 formed with cylindrical shank 1b on one side of diamond bur A, and cutting portion 1a formed on base metal 1 on the other side of diamond bur A extending over a given length from an end of diamond A. A mixture 2 of various abrasive grains with three different grain sizes are secured to cutting portion 1a. Since various abrasive grains with different grain sizes are secured to cutting portion 1a, with the increase of load applied on artificial tooth, the number of abrasive grains contributing to cutting increases, and the machinability is improved. This tendency is equal to the machinability of the diamond bur on the market for cutting human dentin, or dental enamel.

Abstract: A first sheet stacker in which first sheets are stacked and retained by sheet separation claws is formed by a pair of first stacker forming members, and otherwise, a second sheet stacker free from the sheet separation claws is formed by placing second stacker forming members in between the first stacker forming members. Thus, the sheets different in size and thickness can be properly stacked in a single sheet stacker and selectively sent one by one to a printing apparatus such as a general purpose printer without use of any auxiliary sheet cassette or stacker.

Abstract: An ice maker equipped in a refrigerator includes a sealed water tank, a water reservoir supplied with water from the water reservoir by the effect of a difference between water heads until the water reaches a predetermined water level, every time the level of the water reserved therein is decreased below the predetermined water level, a measuring vessel communicated to the water reservoir through a relatively small water path so that the water is supplied thereto from the water vessel by way of the difference in the water heads until the water level corresponding to the water level in the water reservoir is reached therein, the measuring vessel having a lid portion disposed so as to horizontally partition the interior of the measuring vessel at a water level position, an ice tray disposed in the ice-making compartment, and a pump for supplying the ice tray with the water reserved in the measuring vessel.

Abstract: A method of detecting water unsupplied condition of an ice tray of a refrigerator ice maker includes steps of measuring the temperature of the ice tray after the water supply operation of water supply means to the ice tray is executed and determining that the water has not been supplied to the ice tray, where the measured temperature is below a predetermined reference value.