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Publication numberUS3131912 A
Publication typeGrant
Publication dateMay 5, 1964
Filing dateFeb 1, 1954
Priority dateFeb 1, 1954
Publication numberUS 3131912 A, US 3131912A, US-A-3131912, US3131912 A, US3131912A
InventorsSteinbock Jr Edmund A
Original AssigneeEdmund A Steinbock
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Investment mixer
US 3131912 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

3,131,912 Patented May 5, 1964 3,131,912 INVESTMENT MIXER Edmund A. Steinbeck, Jr., Louisville, Ky., assignor to Edmund A. Steinbeck, Louisvilie, Ky. Filed Feb. 1, 1954, Ser. No. 407,337 6 Claims. (Cl. 259-108) This invention relates to improvements in an investment mixer, particularly such a mixer when operated under vacuum or when operated with a vacuum on the materials being mixed.

This invention relates to improvements disclosed and claimed in pending application of Edmund A. Steinbeck, Jr. and Robert Nieman for Investment Mixer, Serial No. 255,704 filed November 9, 1951, now Patent Number 2,777,177.

As stated in said pending application, it has been found that certain advantages, particularly when using certain investment compositions, are obtained when the mixing or spatulation of the ingredients is eifected at a relatively high rate of speed and these advantages consisting in a smoother extremely creamy mix from which the air can be more readily extracted, and in which the time of mixing is materially reduced. The smoother, creamier mix further results in a smoother surface for the mold cavity and a smoother surface on and a' more accurately fitting of the resulting casting from said mold cavity.

Investment mixers of the class of the present invention are generally. motor driven to obtain said higher speed of mixing or spatulation and in the past it has been difficult to effect the proper drive connection between the mixer and the said driving motor. By the present invention the difficulty of interconnecting the parts has been reduced to an absolute minimum so that said driving connection can be readily effected.

The device of the present invention in addition to eifecting the advantage set forth in the preceding paragraph also incorporates means whereby a flow of the mixed ingredients, investment, can be accelerated into the mold forming'device and said flow encouraging means, commonly called a vibrator, obtains its power from the same driving connection as between the motor and mixer.

It is therefore, the principal object of the present invention to generally improve the structure of an investment mixer and the mode of using the same.

Another and important object of the present invention is the provision of means whereby a mixer mixing element and a driving engine may be readily connected and disconnected from one another.

A still further and relatively specific object of the present invention is the provision of an improved coupling or clutch that may be readily coupled between a driving motor and the mixer blade or paddle shaft for efficiently and conveniently actuating said mixing blade or paddle.

A still further object of the present invention is the provision of a vibrator for vibrating an investment mixture with which is associated a mold-forming device for causing a ready flow of the cementitious investment mass from the mixer into the said mold-forming device or its container.

It is also an object of this invention to provide a compact unit for accomplishing the foregoing objects that is simple of construction and economical to produce and acquire while being consistent with the work to be obtained from the device.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made In the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

FIG. 1 is a side elevational view of a complete mechanism for effecting the mixing of investment compositions.

FIG; 2 is an enlarged fragmentary sectional view through the mixer per se and its drive as seen from line 22 on FIG. 1.

FIG. 3 is a transverse sectional view through a portion of the drive mechanism as seen from line 33 on FIG. 2.

FIG. 4 is a vertical sectional view taken on line 44 on FIG. 1.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

Specifically, and referring to the drawings, the complete device of the present invention comprises an electric motor 10 operating at one end thereof a vacuum pump indicated in general by the reference numeral 11. he motor 10 operates at its other end the investment mixer, per se, indicated in general by the reference numeral 12, while the said motor at said end thereof in addition actuates the vibrator indicated in general by the reference numeral 13.

The vacuum pump 11 is suitably enclosed in a housing 14 secured through a supporting bracket 15 to the motor 10. It is to be understood that the motor 10 has one end of its shaft, for the sake of this description, the rear end 28', extending through the bracket 15 into the pump housing 14 for actuating the pump element or elements therein. The pump housing 14 has an inlet 16 connected through an elbow 17, or the like, with the cover 18 of an oiler and filter device 19. The oiler and filter device cover 18 has connected therewith a nipple 29 to which, in turn, is connected one end of a flexible conduit or hose 21.

The pump housing 14 is provided with an outlet, not shown, but with which outlet is connected a mufiier 22 of any suitable or desirable construction.

7 It is believed that the construction and operation of a vacuum pump is well known and need not be ftnther described or illustrated. Briefly, however, the operation of this device is as follows:

Operation of the pump elements within the housing 14 through the motor shaft effects a suction through the flexible conduit or hose 21 and the member or nipple 26, into and through the oiler and filter unit 13-19. The discharge of the air and gases from the pump is through the muffler 22. In order to determine the amount of vacuum being pulled by the pump, there is provided the usual vacuum indicator or gauge 23.

The unit is adapted to be suitably supported on a table or the like through, preferably, rubber feet 24 and 25 respectively secured to and depending from plates or brackets 26 and 27 respectively, secured to and depending from the motor 10 and vacuum pump attaching or mounting bracket 15.

i As seen in 2 the motor jecting fonwardly thereof -to-receive has its shaft 28 proa driving sleeve '29. 29 has its central bore to a diameter to reshaft 28 and is retained on the The sleeve ceive the said motor shaft through a suitable set or dog screw 30 threaded through one side thereof into a keyway 31 formed longitudinally of the said motor shaft 28. The front or outer end of the sleeve bore 32 is outwardly tapered as at B3 forming, in effect, a cup :33 whose inner surface inwardly tapers or is funnel shaped. This cup constitutes one member of the driving clutch, coupling, or the like, as presently be made clear, between the motor 10 and the mixer, per se, 12.

The vacuum mixer, per se, 12, is fully disclosed in the above identified pending application of Edmund A. Steinbeck, Jr. and Robert Nieman', Serial No. 255,704. This mixer, briefly, comprises a cup-like mixing member or container 34 in which the ingredients are mixed with said container or member 34 having interiorly thereof a mixer blade or paddle 35 secured to and carried by a driving shaft 36. The driving shaft 36 is rotatably mounted in a sleeve or bushing 37 pressedinto or cast within a 'hollow upstanding'post or boss 38 from the container or member 34' closing lid or cover 39. In other 'words, the cup or mixing container 34 is closed by the cover or lid '39 in which is journaled a shaft 36 that carries at its lower end and within the cup or 7 container 34, a paddle or mixing blade 35.

The cover or lid 39, to one side of the cylindrical post or boss 38 is provided with an upstanding lug through which is formed an aperture or bore 40 communicating with the interior of the mixing cup or container and which bore 40 receives the end of a coupling or nipple 41 which in turn has connected therewith the other end of the flexible conduit or hose 21. r The cover or lid 39 on the other side of the post or boss 38 is provided with an extension 42 counterbored to receive the lower or inner end of a casting ring or sleeve 43 which is closed at its upper or outer end by a crucible former and sprue former carrier 44. The interior of the casting ring or sleeve 43 is in communication with the interior of the mixing cup or container 34 through an aperture 45 formed through the lid or cover 39.

Upwardly of the bushing 37 the mixing blade or paddle shaft 36 is provided with a threaded reduced portion 46 received in a threaded socket 47 in driven member 48. The driven member 48 has its body portion beyond its threaded socket tapered as at 49 so as to readily enter the driving cup 33' of the driving member or sleeve 29, and inwardly of its outer end the driven member 48 is provided with a circumferential groove 50 receiving a a relatively soft, preferably rubber, ring 51.

In practice, the ring 51 may be what is known as an O ring and when mounted on the driven member 48 has an effective outer diameter less than the diameter of the outer end of the cup 33' while this diameter is greater than the inner end of said cup, wherefore, the said ring will engage the tapered wall of the said cup at a point between its inner and outer ends. It should be noted that the driven member 48 and the ring 51 together constitute or form the second or driven member of the driving clutch, coupling, or the like, between the mixer, per se, and the driving motor.

Secured to the front end of the motor 10, in any suitable or desirable manner, is a housing 54 which supports the mechanism that forms the vibrator 13. As illustrated in the drawings, the housing 54 is somewhat bell shaped and includes a vertical wall 55 from the periphery of which extends or projects the skirt 56. The housing 54 is secured in positions through dog or clamp screws 57 extending through the housing skirt 55 near its edge into engagement with the motor housing circular projection58.-

The housing 54 has upstanding therefrom a sleeve 59 for a reciprocable plunger rod 60. The plunger rod 60 is adapted to be' reciprocated through the sleeve 59and is retained within the sleeve and its path of reciprocation may be controlled by any suitable or desirable means, that shown in the drawings comprising the formation of a slot 61 in one side of the plunger rod 60 cooperating with and receiving the inner end of a screw, pin, or the like 62, carried by and projecting through the sleeve 59. The plunger rod 60 is provided on its upper end with a head 63 of considerable area with respect to the crosssectional area ofthe said plunger rod 60. The head 63 is preferably circular in plan and is provided with an upper surface 64 which, in practice, constitutes the platform for the mixer when the vibrator is being used.

In normal practice, the plunger rod 60 is retained, yieldably, in an inoperative position by means of a coiled spring 65 which encircles the said plunger rod 60 and has one end abutting the upper end of the 59 and its other end abutting the lower surface of the head 63. The normal inoperative position of the plunger rod 60 is determined by the lower add the slot 61 engaging with the screw, pin, or the like 62.

The plunger rod 60 is positioned to overlie the inner end of the drive sleeve 29 and'the said drive sleeve 29 below the said plunger rod 60 is provided with flats, illustrated in the drawings at 66 and 67 and as at diametrically opposite points on the said sleeve. It should be here noted that a single flat may be employed or the number of said flats increased without changing the normal operation thereof. The said flats 66 and 67 cooperate with the circumference of the driving sleeve, as well as with one another, in acting as cams for actuating the vibrator, as will presently be made clear.

In operation and after the materials for forming the investment composition, generally an aqueous solution and powder, have been placed in the mixing cup or container 34, the lid or cover 39tis placed thereon whereupon the vacuum flexible conduit or hose 21 through the nipple or coupling 41 is connected with the said mixing cup or container and the motor started for operating the vacuum pump as above set forth. The vacuum pump withdraws all of the air and other gases within the said mixing container on cup 34 and the casting ring or sleeve 43. In order to insure a completeand effective vacuum within the said parts, all of the joints of the several elements are protected by a g ket, preferably, in the form of an 0 ring. In the drawings, particularly FIG. 2, the said several 0 ring gaskets are respectively indicated by the reference numeral 68.

After the vacuum pump 11 has been placed in operation the user merely raises the investment mixer, per se, from the table or counter and pushes the mixing blade or paddle driving shaft member 48 through its flexible driving element 51into engagement with the inclined or tapered wall 33 of the driving sleeve driving cup or socket 33. This connection may be eifected regardless of the speed of the motor 10 and without in any manner whatsoever slowing down or changing said speed,

as was necessary with the driving connection illustrated in the above identified application. The user will retain the motor and the investment mixer, per se, indriving connection with one; another for the necessary and desirable time of spatulation.

It will be understood that as the mixer paddle or blade 35 is driven, it, through the action of the notches. in its edges, breaks up the investment into ribbon-like layers, thereby exposing such layers to the vacuum for having any entrapped air or gases removed therefrom.

Upon, as noted above, the completion of the mixing of the ingredients, the operator merely withdraws the mixer, per se, from the motor sleeve 29 for thereby breaking the connection'and permitting the mixer paddle 3510 slow down and become idle.

The operator immediately upon retracting or'separating the mixer, per se, from the motor, turns the mixer upside guide sleeve 7 down to place the outer face of the crucible former and sprue former carrier 45 of the vibrator head 63. At the same time, the user downwardly forces the said mixer, per se, and compresses the spring 65 for causing the plunger rod 60 to engage with the surface of the driving sleeve 28 immediately therebeneath. In other words, the plunger rod 60 is now riding on the said outer surface of the sleeve 29 which, as noted above, through the flats 66 and 67 thereon, acts as cams for alternately pushing the rod 60 upwardly and allowing the said rod to drop onto the said flats 66 and 67. Since the motor is rotating at a relatively high speed, this action effects a rapid vertical reciprocation of the said pin or rod 60 and the investment mixer held thereon. This causes a rapid vibration of the mixer and a disturbance in the investment composition overcoming any inertia that may be in said investment composition and causing same to flow from the mixing cup or container 34 through the port or opening 45 into the mold forming housing or casting ring 43. This vibration, in addition, causes the cementitious, semi-fluid investment composition to pack within the said mold-forming housing or casting ring and to pack around the crucible forming portions of the crucible former and around the sprue forming pin as well as around the pattern at the inner end of the said pin, all as is well known in the use of a vibrator.

From the foregoing it will be noted that there has been provided a compact unit for effecting the mixing of ingredients that form and constitute an investment composition and in which the drive between said mixer and its driving engine or motor is readily effected. It will further be noted that the compact unit readily removes any air or gas that may be within the several housings of the mixer and casting ring and entrapped in the ingredients constituting the investment composition. At the same time, there is provided a vibrator for insuring a motor having a shaft,

motor to be operated thereby, a coupleable driving member of a separable friction drive device secured to the other end of the motor shaft, an investment mixer including a driven mixing element, a coupleable driven member of the separable friction drive device carried by the investment mixer driven mixing element for frictional engagement with the driving member of the separable friction drive device, and means connecting the vacuum pump and investment mixer providing a suction passage to establish and maintain a vacuum in the mixer.

2. A device of the class described the combination of a motor having a shaft, a vacuum pump secured to the motor and connected to the shaft at one end of the motor to be operated thereby, a coupleable driving member of a separable friction drive device secured to the other end of the motor shaft, an investment mixer including a driven mixing element, a coupleable driven member of the separable friction drive device carried by the investment mixer driven mixing element for frictional engagement with the driving member of the separable friction drive device,

and a vibrator carried by the motor including an actuating device secured to and actuated by the motor shaft at the end thereof with which the separable friction drive device coupling member is associated.

3. A driving connection between a motor and an investment mixer comprising the motor having a driven shaft, a sleeve secured to said shaft for rotation therewith,

on the surface or platform 64 plunger for effecting vertical rec'procation of the plunger relative to the housing.

5. A driving connection between ment mixer comprising the motor having a driven shaft,

vertically reciprocable plunger carried by said housing, means on said sleeve within the housing engaging the plunger for eifecting vertical reciprocation of the plunger relative to me housing, and yieldable means for normally separating the plunger and sleeve.

. 7 '8 said sleeve within the housing engagingthe plunger for 1;784;307 'Nelson' et a1. Dec. 9, 1930 effecting vertical reciprocation of the plunger relative '1,863,977 Forde et a1. June 21, 19.32 to-the' h ousing; a head secured to the plunger upwardly 2,036,713. McBath' Apr. 7, 1936 of the housing; and yieldable means between the plunger 2,453,914 Hollenback Nov. 16; 1948 head and housing for normally elevating the plunger to 5 :2,556;263- Fiorini June 12; '1951 a-point out of operation with the sleeve. 2,562,805 Martinez July 31, 1951 g 7 r 2,605,086 Marco July 29, 1952 References Cited in the file of this patent 2,637,936 en May 12, 1953 NI STATES PATENTS 2,666,307 Higert' Jan. 19; 1954 2,690,246 Kelleigh Sept.- 28, 1954 Steinbeck et al Jan. 15, 1957 244,091 Tenney Ju1 12, 1881 10

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3211432 *Apr 23, 1962Oct 12, 1965R Dental Products Inc VanVibrating table construction
US3358971 *Jun 21, 1965Dec 19, 1967Whip Mix CorpInvestment mixer
US3366369 *Oct 7, 1966Jan 30, 1968Giacinto Guido FinaDevice for mixing and transferring under vacuum special pastes and gypsum for use in dental and jeweller's art
US3572641 *Feb 3, 1969Mar 30, 1971Peterson Edwin FRotary vibrator with adjustable weight means
US3640510 *Sep 26, 1969Feb 8, 1972DegussaVacuum stirring device for dental materials
US4758096 *Dec 8, 1986Jul 19, 1988Mit AbApparatus for mixing bone cement in vacuum
US4889432 *Feb 7, 1989Dec 26, 1989Roosevelt PattersonDental mixer apparatus
US4973168 *Jan 13, 1989Nov 27, 1990Chan Kwan HoVacuum mixing/bone cement cartridge and kit
US5121990 *Dec 19, 1986Jun 16, 1992Jacques GuietDevice for the preparation of a paste
US5328262 *Feb 3, 1993Jul 12, 1994Mit AbMethod for producing reduced porosity bone cement
US5348391 *Nov 16, 1993Sep 20, 1994Murray William MManual bone cement mixing method
US5368386 *Nov 16, 1993Nov 29, 1994Murray; William M.Manual bone cement mixing device
US5395167 *Nov 16, 1993Mar 7, 1995Murray; William M.Manual bone cement mixing system
US5409311 *May 17, 1993Apr 25, 1995Vosschemie GmbhDevice for the production of medium-viscous or more highly viscous dual-component of multi-component compounds by intermixing the components
US5472445 *Sep 20, 1993Dec 5, 1995Zimmer, Inc.Device for minimizing porosity in bone cement utilizing centrifugation and vacuum
US5501520 *Apr 26, 1994Mar 26, 1996Mit AbDevice for producing reduced porosity bone cement
US5549381 *May 19, 1995Aug 27, 1996Hays; Greta J.Method and apparatus for mixing polymeric bone cement components
US5797680 *Sep 5, 1996Aug 25, 1998Murray; William M.Manual bone cement mixing system with vacuum pump start-stop device
US6120174 *Jan 14, 1999Sep 19, 2000Bristol-Myers SquibbApparatus and method for mixing and dispensing bone cement
US6994465Mar 13, 2003Feb 7, 2006Stryker InstrumentsMixing assembly for mixing bone cement
US7645066Dec 12, 2005Jan 12, 2010Stryker CorporationMethod of mixing bone cement with two mixing paddles
US7967499Jan 12, 2010Jun 28, 2011Stryker CorporationBone cement mixer with two paddles, the paddles arranged to limit longitudinal movement
USRE35276 *Nov 23, 1992Jun 18, 1996Chan; Kwan-HoVacuum mixing/bone cement cartridge and kit
DE1607783B *Nov 21, 1967Jan 28, 1971Angelo RavasiVakuummischer fuer zahntechnische Anwendungen od. dgl.
EP0230832A1 *Dec 22, 1986Aug 5, 1987Jacques GuietMethod for making a paste based on alginate, plaster or similar substances, and device for carrying out said method
U.S. Classification366/65, 366/112, 366/139
International ClassificationB01F11/00, B01F7/16
Cooperative ClassificationB01F7/1695, B01F11/00
European ClassificationB01F7/16S, B01F11/00