| 摘要 |
277,675. Pieper, O. H., and Pieper, A. F. Sept. 20, 1926, [Convention date]. Dental instruments; appliances for illuminating cavities; cauterizing-appliances.-Relates to switch handles or instrument holders for electrically-heated dental or like instruments such as pluggers for guttapercha stoppings, inspection lamps, or cauteries, and more particularly to the means for securing the tool in place in the holder, the means for making electrical contact with the tool, and the means for insulating the user's hand from the heat of the tool and the holder. The handle 1 is formed with a threaded neck 19, Figs. 2 and 6, formed with an L- shaped slot 24, a resilient split sleeve 21, mounted within the neck 19, is formed with bevelled ends which are engaged by bevelled surface 24, 23 on the handle 1 and on an external clamping-ring 22 respectively, so that when the ring 22 is screwed down on the neck 19 the sleeve 21 is contracted so as to clamp the base member 26 of the tool. The upper portion of the neck 19 also is engaged by the bevelled surface 23 so that it closes on and grips the sleeve 21. The sleeve 21 is formed with flat surface 21a and is positioned so that the slot 21<c> therein is in alignment with the vertical portion of the slot 20 in the neck 19 so as to increase the binding action of the. parts. The tool is fitted with concentric contact members 28, 29. The outer contact member 29 engages within a flared split sleeve 10 mounted on a resilient conducting strip 8; the central contact member 28 may be put into connection with a second resilient conducting strip 6 by upward movement of a sleeve 18 which carries a button 17 projecting through a slot 16 in the handle 1. The conducting strips 6, 8 are held in grooves 4 in a core 2 of insulating material and are covered on their outer faces bv insulating strips 7, 9 held in place by rings or bands 11 fitted in grooves in the core 2. To protect the hand of the user from excessive heat the tool is fitted with an insulating collar 32, the clamping ring 22 is covered with insulating material 22<b>, and the switch sleeve is formed of insulating material. A spiral guard 33 round the base of the tool may also be provided. The tool may be turned in the handle, after slacking off the clamping-ring 22, so that the tool and the switch button may be brought into convenient relative position. A known construction is referred to wherein a tapered shank on the heating tool or instrument is received in a split collet in the handle and the latter is provided with two contact strips cooperating with terminals on the instrument. |
