US 1670026 A
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' May 15, 1928. 1,670,026
(LA. DE LANO DENTAL WAX EXPANSION CABINET Filed Feb. 25, 1927 2 Sheets-Sheet 1 INVEN TOR.
A TTORNE Y.
May 15, 1928. I 1,670,026
c. A. DE LANO 1 DENTAL WAX EXPANSION CABINET Filed Feb. 25, 1927 v 2 Sheets-Sheet 2 w INVENTOR. 6. AD? A/VO,
ATTORN Patented May 15, 1928.
UNITED STATES COURTLAND A, DE LANO, OF CEDAR RAPIDS, IOWA.
DENTAL WAX EXPANSION CABINET.
Application filed February 25, 1927. Serial No. 170,956.
My present invention, in its broad aspect, has reference to improvements in methods and apparatus for controlling the thermal expansion and contraction of dental wax patterns and investments in which the castings are made thereby to obtain more perfect castings of inlays, crowns, bridges, plates, saddles, and the like than has heretofore been attained.
, The factors of expansion and contractio of materials from a given mean for given temperatures is a known quantity easily determinable. Heretofore the contraction of gold and other metals from the molten to the solid state in castings has largely been made up by the addition of quantities of the metal during the process of cooling to make up the loss by contraction. This method has not, however, succeeded in wholly compensating for variations due to thermal expansion and contraction in the wax forms or patterns and investments. Consequently perfect dental castings are obtainable only by the exercise of a high degree of skill.
' and patience.
My present method consists largely in controlling the temperature of the wax pattern or form and the investment therefore from which the casting is made so that contraction in the material of the casting in its change from the molten to the solid state can be largely compensated for by expanding the wax pattern or form and the investment so that aknown means will be attained which will be an exact reproduction in size and de tails of form of the cavity, or other oral condition to be treated.
The apparatus used with my present invention consists primarily in an improved and unique collapsible cabinet in which wax patterns and investments are adapted to be raised to a predetermined temperature to expand the same to the desired degree so that the final casting will be large enough to be readily slipped in place free from errors due to contraction. The degree of contract tion of gold from the molten state to the freezing state, and the expansion from the freezing state to normal atmospheric temperature is approximately two per cent, but by careful manipulation in the casting whereby the mold is filled until the casting is solid enough to hold its form the loss due to contraction can be almost, but not quite, eliminated. Consequently by properly expanding the wax pattern before the object is cast the error factor due to thernjial contraction and expansion of the metal of the casting can be compensated for (the above mentioned loss eliminated). For instance when it is desired to prepare an inlay for what is termed an M. O. D. cavity (meaning a cavity on the front or mesial side, the occlusial or top side, and the distal or back side, or in other words, a cavity which is somewhat U-shaped) the pattern is commonly made and the gold cast in the usual manner which gives an inlay from front to back which is so shrunken that it will not ordinarily fit the cavity. To prevent this condition a copper band is placed around the tooth into which the wax is run so that when the band is filled the shrinkage is on the occlusial surface from the lingual to the buccal side, or away from the tooth and toward the band. This is exactly what is wanted since by utilizing my cabinet the pattern can again be expanded to its proper form, the investment made, and the casting of the inlay completed at the proper temperature to produce in the final casting an exact reproduction of the cavity.
In the drawings wherein my cabinet is illustrated Figure 1 is a perspective view of my cabinet, the covering therefor being removed to show the interior,
Figure 2 is a perspective view of my cabinet with the cover applied thereto,
Figure 3 is a perspective view of my cabinet partly collapsed,
Fig. 4; is an end elevation,
Figure 5 is a front view of my cabinet when collapsed, and
Figure 6 is a partly diagrammatic plan view of the heating units of my cabinet.
In the drawings wherein like characters of reference are used to designate like or similar parts throughout the several views;
The numeral (1) designates the base section of my cabinet which has a bottom (:2), aback (3) and sides (4). the front is hinged thereto and has ventilating openings (6) therein. Adapted to be positioned upon the base section is a floor (7) having ventilating openings (8) therein. The floor is freely removable.
Hinged as at (9) to the back (3) of the base (1) is a back wall (10), and hinged as at (11) to the respective sides are side walls (12). The back wall and side walls are adapted to be locked together along their meeting edges by fittings (13) to form a three sided compartment Hinged as at (14:) to the back is a shelf (15), and to the top edge of the back is also hinged as at (1.6). a relatively narrow cover element (17) which rests (when the compartment is set up) ontriangula-r side Wall extensions (18), hinged to the side Walls at (18 i i From the. foregoing it. Will be seen that the. compartment is collapsible by simply unlocking the fittings (13'), dropping the sidewall extension (-18) and side walls (12) on'the base sections, and dropping the cover (17 and shelf (15) and the back'wall (10)" thereon. A swinging bracket (19 is pro vided for holding up the shelf, (15). i
The openfront, and. partially open top of my. compartment is closed by. a heavy black sateen (or other material). curtain (20) having lass covered peep opening (21) and a light fitting (22) extending to the interior the cabinet. Another covering element having sleeves (24) is provided for receiving the arms of an operator, and to that end elastics (2 5) are provided in the edges to afford a close fit tothe arms of said operator. The curtain (20) is Weighted along its edges at (26) shown in: dotted lines, and the covering element (23) may have its edges wired. (not shown) to further support the same if .desired/ The, cover curtain (20) is separable from covering element (23,)so that'it may be raised, toad mit objects to the cabinet.
he entire constructionof the cabinet is of some heat resisting material such as sheet metal, composition boarch or other fire resisting material. i
in the base section of my cabinet is mountechby means of brackets (27)., a tray (28) having a plurality of ventilating openinns On the tray are. mounted sets of heating coils connected with thlEI'Il'lQr static devices and pilot lights (32) all in. circuit with' a detachable'plug with a power line Theelements are sivitch controlled as at sothat the heat may be properly (either manually'or automatically) regulated. V
In operation all. of; the tools and instruments used in dental casting. are placed in the cabinet, such. as casting flasks, models, investment miner, rubber ivater bottlerplasten bowl, casts, patterns, brushes, slabs Weighing. devices, spruesj, formers, pliers, ard the like. These are. all raised to-"a desired predetermined temperatureand maintained at that temperature throughout the Whole operation of casting, the inlay or the like. The operator inserts'hi s arins through the sleeves (24,) and follows his Work throng-lithe peep opening (21). The temperature of the. cabinet is regulated to cause theaters.e pansi 9 he and n tments to attain an absolutely accurate castmg.
lVhile I have, in the foregoing, described and illustrated the preferred embodiments of my method and apparatus with particu la-rity, I do not desire thereby to be limited in the essential bi'oad concept of my inventionexcept as may be indicated by the scope of'the claims appended thereunto.
l. A collapsible cabinet comprising. a base.
portion, a removable floor on the base por-' tion, a plurality of vvall members hinged to the, base portion to form a three sided com} partment above the removable floor, trianguw gular extensions hinged to certain of said \vall members, tqp'hinged to the other Wall members and slantingly suppolted 'by the extensions when the cabinet set up, heating elements carried by the base mem hers, and curtaining devices removably arranged about the compartment to close} the same. '2. The combination With a cabinet having a heating element therein and formed with an open side, of a Weighted fahric element attached thereto to form a curtain for the openside. to retain the heat in the cabinet, and another fabricelement having fabric sleeve members and detached from the curtain to givev access to the cabinet for a persons hand. and arms, the Weighted fabric element overlapping the latte'rfabric element. i
3. A collapsible cabinet comprising a hol loiv base, a removable floor on the base, a plurality of all members hinged to the base to form a compartment above the remov able floor,'ti'iangular extensions hinged to certain of said wan members, atop hinged to the. other Wall members and slantingly supported by the extensions when the cabinet is set up, heating elements carried in the liOllOW base, a fabric curtain covering the compartment, and fabric sleeve members giving access to the cabinet for a persons hands and arms. 7 i
i 4. In a dental wax expansion device. the combination ofa cabinet having an open side, a pair ofcoverinq elements separate from eachother and arranged one above the other, the upper covering element being Weighted to normally overlap the lower element, to close the open side of the cabinet, sleeve members on the lOWGl element for receiving a persons hands and arms and means for heating the cabinet. 2
5. a dental ivax expansion device, the combination of a cabinet having an open side, apair of covering elements separate from each other and; one. arranged above the other in overlapping relationship to close the open side of the cabinet, the upper covering element being Weighted along its lovver d e, slee members e th ov lem n for receiving a persons hands and arms and means for heating the cabinet.
6. A collapsible dental Wax expansion device comprising a cabinet having a base, a back Wall and two side Walls hingedly connected to the base and relatively separate from each other to fold down upon the base, means for connecting the side Walls with the back Wall in set up position, triangular extensions hingedly connected to the side walls, a top hinged to the back Wall and slantingl supported by the triangular extensions and a heating element in the base.
In testimony whereof, I aflix my signature hereunto.
C. A. DE LANO.