US1493692A - Dental casting machine - Google Patents

Description

May 13 A, 1924.

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May 13 1924.

T. A. MlxoN DENTAL CASTING MACHINE Filed Sept. 1`o

1921 3 Sheets-Sheet 2 n N NV w N www w IN 0. NM N 7M w M M M ne d@ N w w NNNN N May 13, 1924. i 1,493,692

T-. :A. MlxoN DENTAL CASTING MACHINE Filed Sept. l0 1921 I5 Sheets-Sheet 5 TEIDMAS A. ,'If`, @E ATILMTA, GEGRGIA.

DENTAL {IiiSTNC-f MACHNE.

' Iapplication nlei September 10, 1921. Serial 1%' o. Naas-t.

To al? @alzo/m t may concern: forated reducing coupling 4 threaded on the Be it known that l, THOMAS A. Minori, a exterior to engage the threaded walls of citizen of the United States, residing at said hole 3 and having a central depression Atlanta, in the county of Fulton and State 5 interiorly threaded for engaging the hola of Georgia, have invented certain new and W threaded member 6 ofan adapter 7` 60 useful Improvements in Dental Casting Mawhich may be removed quickly if desired by chilies; and I do hereby declare the followunscrewing it, in orderthat, in place of the ing to be a. full, clear, and exact description sald adapt-er 7, atlask or casting cup 70 of of the invention, such as will enable others large size may be fitted directly into said 10 skilled in the art to which it appertains to Cavity 2; The adapter 7 has an orifice 8 @5 make and use the sume, extending completely through it from the This invention relates to dental casting top Surface to the lower end of the member machines or the like, and more particularly G. The 0111301 edge 9 Of the adapter' I'SSS. to casting machines of this type in whichy snugly upon the top surface of the base 1 l5 air pressure is applied on top of thel casting alonnd the margin of cavity 2. ln the top 70 during the casting operation and simultane- 0f lille adapter is a Countersink or cavity 10 ously air is withdrawn from the mold. ildilpld t0 rece-ive a flange 11 of a casting The Object of this invention is t0 make cup 12. The casting cup 12, or the'like, is

perfect Castings of gold inlays, bridges` to contain themold material in which the crowns, abutments, and partial, or full metal mold 1s formed and in this mold the metal dentures, used in the dental profession; or t0 be Cast Ina-y be melted, as by a blow pipe in the jewelry trade to enable various artiflame. 'y cles of precious metal, where a wax or other Connected to the lower reduced portion of form of disappearing pattern is used. to be ille reduc-111g COUpling 4 rby the union couaccurately @ist pling 13 is a pipe 14 the other end of which 30 The invention comprises a mold flask, or iS COIlneCted by a similar coupling 15 to a casting cup, in combination with mechanism threaded hollow nipple 16 projecting from for applying nir pressure to the top 0f the the Of a. SllCtlOD Pump `Cylinder 17, casting in the mold and Simultaneously thus establishing communicationbetween the withdrawing air from the mold cavity pump cylinder and the casting cup. The 35 through the bottom of the cup. t com- Pump Cylinder 17 may be secured firmly to prises, also, various subcombinations and'deille tOp 0f the base 1 by means of bolts or tails of construction more fully set forth in piller fastenngs passed through anges 18 the ensuing description, illustrated in the 1 I1t0 the bilSn l. In the embodiment of the accompanying drawings and defined iu the invention described the cavity 2 is located 90 appended claims. substantially along the center line of the In the accompanying drawings in which base l adjacent 011 @11d tlleleOf, While the' like reference characters designate like parts pump cylinder 17 is secured to said base at throughout the Several views; one side of the center line for a purpose to 40 Figure 1 is a. top plan view of the combe presently explained. Rising on opposite 95 plete apparatus; Sidesfof the cylinder 17 are upright guiding Figure 2 is a longitudinal section on the standards 19 which, in the" present instance, irregular line 2-2 of Figure 1; are utilized for securing the pump cylinder Figure 3 is an elevation of the apparatus 17 down upon the 'base 1. as shown, the

viewed from the right hand side of Figures lower ends of said standards being reduced, 100

1 und 2; passed through perforations in flanges 18 Figures 4. 6 and 7 are details of flasks, and threaded into base 1. Within the cylor casting cups, with associated equipment. inder 17 is a ,piston 20, suitably packed, and

In the. particular embodiment of my inattached to a piston rod 21, which extends vcntion illustrated in Figures 1 to 3, nuupward through a central opening in the 105 meral 1 indicates a base, said 'base having a cylinder head 22 secured to. the top-'of the cavity 2, preferably in the longitudinal cencylinder in any approved manner, but shown ter line of the base and circular in form as as screw` threaded thereto. Above the cylshown, the bottom wall of said cavity havinder head 22 the piston rod 21 may be cone5 ing a threaded hole at 3 closed by a pernected toa U-shaped yoke 23, the limbs 1,10

23*1 of which extend downward, parallel with each other, on opposite sides of the piston, and have perforated terminals 24 extended at right angles, the standard 19 passing through said perforated terminals `24 vand serving as guide standards forthe yoke. Coil compression springs 25 are disposed between the perforated terminals 24 and the base flange of the pump cylinder, said sirings exerting their elastic. force to push tlie yoke 23 upward and thereby carry the piston 20 upward. Perforations 22a formed in the cylinder head 22, allow free esc-apeA of air. The means forsecuring the yoke 23 to the piston rod comprises a collar 26 0n the piston rod engaging the under side of the yoke; a large washer 27 engaging the top side of the yoke, said washer being locked down by a nut 28. Secured tothe top of the piston rod v21 is a suitable handle 29 Which may receive the pressure of the hand to force the pump piston downward.

Rising from that end of the base l which is opposite the cavity or depression 2 is a pair of bearing lugs 30, 30, spaced equally on opposite sides of a center line that intersects the axis of cavity 2, between which is pivoted a cover and trip-carrier arm 31 by means of conical bearing pivots 32 or by other suitable means. The said carrier arm 31 when in operative position extends upward from its pivotal bearing and then turns substantially at right angles and extends over the base l in substantial parallelism therewith. At the end of said carrier arm 31 is a suitable hand-hold 33 by means of which the arm may be manipulated. As shown clearly in Figure 2 the arm is hollow for a portion of its length providing an air chamber as illustrated at 34. Tapped into the arm, preferably at the end ofthe chamber y34 nearest the pivot, is

a fluid conductor 35 for the purpose 0f admitting air under pressure into the hollow portion 34 of the arm. In order to regulate the pressure of the air flowing into the chamber 34 I may provide a suitable reducing 'valve 36; and in order to determine the pressure of the air entering the chamber 34 of the hollow arm I may provide any suitable pressuregauge 37. The end of conductor 34 opposite its connection to the lever is adapted to' be coupled to a flexible pipe leading from a source of air or other gas under pressure. Communicating with the chamber 34 preferably at its upper end and carried on the under side of the arm 31 is a tubular extension 38 fitted air tight t0 the hollow arm and having a conical or other suitable valve seat 39 at its upper end. Telescoped into the tube 38 is a second tubular member 40 which may have a spheroidal end 41, engaged by a coupling member 42 having a correspondingly curved opening and an interiorly screw-threaded maaeaa flange 43 adapted to be seated over the spheroidal end and to be coupled with an exteriorly threaded flange `44 on a cover plate 45 which is provided with an asbestos or other -refractory centrally perforated packing 46 on its under side. The interior of the flange 44 is also curved spherically and engages the exterior of the head 4l. Thus, the cover plate 45 is connected by means of the coupling 'member 42 to the head 41 of the tubular section 40 so that it has a self adjusting universal movement thereon. A refractory nipple 41 may be seated in thelower end of the tube section 40. A coil spring 47 disposed between the coupling member 42 and the lower end of the extension 38 keeps the Said members 38 and 40 extended, relatively, so that the valve 48, which is adapted to seat on the valve seat 39, heretofore referred to, is closed. The said valve 48 is provided with a conical head, a stem 49, a shoulder and a threaded extremity 51, the said stem 49 below the shoulder 50 being free to, slide a limited extent in a perforated diaphragm or bridge 52 which is connected to the tubular section 40. The said bridge 52 may be a plug having perforations therethrough, an` integral web, or any other suitable construction, fixed to the tube section 40, which will permit the passage of air. To the threaded extremity 51 of the shank 49 of the valve is secured a nut 51, preferably relatively heavy, and tending to move the valve 44 toward its seat. By this construction the spring 47 will extend the tubes 38 and 40. normally, until the extension is checked bv engagement of the head of the valve 48 with the seat 39, thus maintaining the valve closed except when pressure is applied to the free end of the tube section 40.

A pull spring 53, having one end attached to lug- 54, on lthe base 1. and the other end attached to the arm 31 above its pivot at 54a exerts its tension t0 swing the arm upward about its pivotal connection with bearing lugs 30, 305 to lift the arm 31. .In order to limit the upward movement of the arm 31. a quadrant member 55, formed on 0r secured to it, extends below the pivotal axis at one side, said quadrant member having' a hole 56 and a lug 57, separated about 9() from each other. lVhen the arm is down. as it is in casting position, a spring-actuated latch'pin 58 carried by and extending through the bearing lug 30a is in alinement with the hole 56 and will lock the arm in that position. When the latch pin 58 is pulled outward the tension of spring 53 moves the arm upward until the lug 57 engages with one edge of the bearing lug- 30n and brings the arm to rest with the handle 33 projecting upward; A

` A trip finger 60 is secured to arm 31, in such manner as to be adustable transversely of the arm in a plane perpendicular to the base l, that is, when lthe arm is in its lowered position and the base is-horizontal, the linger G() may be adjusted vertically. its shown, the arm 31 is irovided with an opening at one side of its longitudinal center within which the finger may slide longitudinally of itself, and a set screw 61 is )rovided for clamping the finger in the desired position.

Pivoted on the cylinder head 22 is a latch having an arm provided with a latch head 62 and a trip arm 63 extending substantially at right angles `to the head-carrying arm inta the path `of the end of the trip finger 60 on the arm 3l when said arm 1s brought down to operative position. A spring such as 64 maintains the latch constantly in latching position. The latch head 62 engages overtlie washer 27, :or other suitablelateh engaging member, carried by some part connected to the piston rod 21.

Referring now to Figures 1, 2 and3, the operation of the means thus far described 1s as follows: The mold having been suitably.

formed in the castingfcup 12 in the known. manner, the metal is fused in the mold by a blow pipe. At that time the arm 31 is in elevated position and suction um piston 20 is locked down, in the position s viovvn in Figures l and 3, byV the latch, the pump piston having been previously depressed by pressure of the hand exerted upon the handle 29. At this time the tube sections 38 and 40 are extended by spring 47 and the valve 48 is closed upon the seat 39. As soon as the metal has been fused and run into the mold cavity thehand-hold 33 of the arm 31 is seized and the arm 31 pulled downward, bringing the cover 45 on top of theflask or casting cup 12. The relative position of the top of the casting cup with respect to the rest of the mechanism describedv is suoli that the tube 40 will be pushed slightly into the tube 38 and the lvalve 48 raised from its seat by reason of the engagement of the bridge or web 52 with shoulder 50p on the valve stem letting air under pressure flow downwardthrough the tubes 38 and 40 and through the orifice in the end of the tube 40, cover cap and packing, into the mold. The

cover 45 will adjust itself absolutely to the released the spring 25 bearing upon the yoke 23 moves the piston upward, the air above the piston escaping lthrough the openings 22g. rllhuspressure is reduced on the under side ofthe piston and air drawn from the mold so that no air can be encased' or occluded in the duid metal being cast or prevent the fluid metal from entering the finest interstices of the mold. Pressure of the compressed air on the top of the metal, and simultaneous exhaustion of the air through the mold material, insure the perfect filling of the mold contour so that' the negative contour of the mold is reproduced exactly and with the greatest nicety asa positive in the casting.

In order to accommodate molds of different size and adapt casting cups or fiasks of diderent size to this apparatus, a variety of cups with appropriate adapters have been provided. ln case a very large flaskor casting cup, such as is shown at 7 0, is to be used, the adapter 7 is removed, the cup 70 seated in the cavity 2 and the adapting cover 71 applied to said cup 70, The said cover has a central opening surrounded by a flange' 72 of lesser diameter than the cover 45 so that the same cover 45 which is adapted to fit over a smaller casting cup may be adjusted to this large'cup 70. The height of the cup 7 0 plus the height of the cover 71 is equal to the distance from the bottom of cavity 2 to the top ofcup 12 seated on vadapter 7. In case it is desired to use a casting cup 73, which is still smaller than the cup 12, a second adapter 74 is fitted onto the adapter' 7. On the under side of the adapter 74 is a flange 75 surrounding an opening in the adapter, which flange fits the countersink or cavity 10 in the upper side of the adapter 7; and on theupper side of the adapter 74 is a cavity which lits a flange 76 formed around the opening in the bottom of said cup 73. By this construction the cup 73, which is shallower than the cup 12, may be brought with its upper edge to the same height above the base 1 as was the cup 12 seated on the adapter 7. In the same manner a still smaller cup 77 of less height' than the cup 73 may be brought into position so that its upper edge will be the same distance above the base 1, as the top of the cup 12 seated yon the adapter 7 by adding a second adapter 78, as indicated in Figure 7. Thus, different sizes of casting cups by the use of adapting bases or adapting covers may be utilized on the same mechanism Without making any other adjustments.

Having described my invention-in such manner as to enable those skilled in the art to make and use the same what I claim and desire-to secure by Letters Patent is:

1. In casting apparatus, a movable hollow carrier adapted to be connected with a source of fluid under pressure, a perforated flask cover having communication with the interior of said carrier, a universal joint between said carrier and said cover, and a valve for controlling the flow of fluid under pressure to said cover.A

2. In casting apparatus, a movable, hollow carrier adapted to be connected to a source of fluid under pressure, a perforated flask cover having conn'nunication with the interior of said carrier, a universal joint between said carrier and cover, a normally closed valve controlling communication between the carrier andthe perforated cover, and means for opening said valve responsive to pressure of the cover on the flask.

3. In casting apparatus, a movable hollow carrier adapted to be connected to a source of fluid under pressure, a longitudinally yieldable tubular member communicating with the hollow carrier, a perforated cover plate carried by the end of said tubular member, a valve for controlling the passage of fluid from the carrier into said member, and means actuated by a yielding movement of said member for unseating said valve.

t. In casting apparatus, a movable hollow carrier adapted to be connected to a source of fluid under pressure, a tubular extension from said carrier, a valve seat between said extension and carrier, a tubular telescoping section movable longitudinally of said eX- tension, a valve adapted to engage said valve seat, connections between said telescoping section and valve, a perforated flask cover-carried on the end of said telescoping section, and a yieldable means for extending said telescoping section.

5. In casting apparatus, a movable hollow Vcarrier adapted to be connected to a source of fluid under pressure, a tubular extension from said carrier, avalve seat between said extension and said carrier, a tubular telescoping section movable longitudinally of said extension, a valve adapted to engage said valve seat, connections betweenv said telescoping section and valve, a )erforated flask covei` connected to the end o said telescoping section, and a coiled compression spring surrounding said telescoping section between the endof the extension and the flask cover. w

G. In casting apparatus, a movable hollow carrier adapted to be connected to a source of fluid under pressure, a tubular extension from said carrier, a valve seat between said extension and said carrier, a telescoping section slidably connected with said extension, a valve adapted to be seated in said .valve seat, connections between said telescoping section and valve, a perforated cover universally jointed to the free end of said telescoping section, and a coiled compression spring surrounding said section between the cover and the end of the extension.

7. In casting apparatus, a movable hollow carrier adapted to be connected to a source of fluid under pressure, a perforated flask ,cover universallv connected thereto and having communication with the interior thereof, means to control the passage of fluid under pressure to said cover, and a reducing valve for regulating the pressure of the fluid in tlie carrier.

8. In a casting apparatus, a movable hollow carrier adapted to be connected to a source of fluid-under pressure, a perforated.

flask cover universally connected therewith and having communication with the interior thereof, means to control the passage of fluid under pressure to the cover, a reducing valve for regulating the pressure of fluid in the carrier arm, and a pressure gauge adapted to indicate the pressure in said carrier.

9. In casting apparatus, a base adapted to support a flask, a carrier arm pivoted to said base, a perforated flask cover uni-` versally carried by said carrier arm, means for controlling the passage of fluid under pressure to said cover, and means for norlmally elevating said arm with a yielding force to remove the cover from the flask.

lO. In casting apparatus, a base adapted to support a flask, a carrier arm pivoted to the base, a perforated flask cover carried by said carrier arm, and means to control the passage of fluid to said cover, a spring normally acting to elevate said carrier to remove the cover from the flask, and a device to hold the arm in its lower position with the cover pressed upon the flask.

11. In casting apparatus, a base adapted to Sustain a flask, a pair of bearing lugs elevated from the basea carrier arm pivotetd between said bearinglugs and carrying a perforated flask cover, means for controlling the passage of fluid under pressure to said cover, a spring arranged to exert its tension to elevate the arm, a quadrant on the arm extending below the pivot thereof, a stop on said quadrant adapted to engage one of said lugs when the arm is elevated, and cooperating latch means on said quadrant and one of said bearing lugs adapted to hold the arm in its lowered position with the cover pressed upon the flask.

12. In casting apparatus, a base having a perforation and adapted to support a flask over said perforation, a carrier arm movably mounted on the base, a flask cover mounted on said carrier, a pump cylinder vmounted on said base, a conduit connecting said cylinder with the perforation in the base, a piston in the cylinder, yieldable :means for moving said piston, a latch for `holding said piston against the tension of said yieldable means, and a trip carried by the arm arranged to release the latch at the `time the cover is pressed upon the flask.

13. In casting apparatus, a base havin a perforation and adapted to support a flasl over said perforation, a suction pump cylinder mounted on the base, a conduit connecting the cylinder with the perforation in the base, a piston in said cylinder, a piston rod connected to said piston, a yoke ysecured to said piston rod, means for guiding the yoke, compression spring means surrounding the guiding means and acting upon the yoke to operate the piston, a latch for holdin-g the piston retracted and the spring means under compression, and means to release the latch.

14. In casting apparatus, a base having a depression, an orifice in said depression, a suction device kmounted on the base, a con.- duit connecting Said suction device with the orifice in said depression, a removable adapter having a central perforation adapt ed to communicate with said oriiice, said adapter being adapted to receive a flask on its upper surface. A

In testimony whereof aiiix mv si nature.

THOMAS A. M1 ON.

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