US3222037A

US3222037A - Amalgam agitator and dispenser

Info

Publication number: US3222037A
Application number: US145878A
Authority: US
Inventors: Charles J Thiel; Louis J Michaels
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-10-18
Filing date: 1961-10-18
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07

Description

Dec. 7, 1965 c. J. THlEL ETAL 3,222,037

AMALGAM AGITATOR AND DISPENSER Filed Oct. 18, 1961 2 Sheets-Sheet 1 IN VEN TOR?! o WZM ATTWI/V:

Dec. 7, 1965 c. J. THIEL ETAL 3,222,037

AMALGAM AGITATOR AND DISPENSER Filed Oct. 18. 1961 2 Sheets-Sheet 2 lllil United States Patent C) 3,222,037 AMALGAM AGITATOR AND DISRENSER Charles J. Thiel, 625 6th Ave, and Louis 5. Michaels, 1210 6th Ave., both of Dayton, Ky. Filed Oct. 18, 1961, Ser. No. 145,878 15 Claims. (Cl. 25972) This invention relates to apparatus for agitation and dispensing, and more particularly the invention is directed to apparatus for the preparation and application of amalgam in the field of dentistry.

The material with which a tooth is filled is called amalgam and comprises a mixture of mercury and an alloy which is at least 68% silver. The alloy is in a powder form which may have been prepared by a dental supplier into pellet form, each pellet weighing six grains, for example. The mercury and the alloy are maintained separate from one another until it is time to fill a tooth. For many years the dentist or his assistant prepared the amalgam by placing the amalgam with a drop of mercury in a mortar cup and mixing the two together with a pestle.

The dentist would then place a small portion of the amalgam mixture in an amalgam dispenser and apply it to a tooth. After the first portion had been packed into the tooth, another small portion of amalgam was placed in a dispenser and applied to the tooth. This process was continued until the tooth had been filled. As each portion of amalgam was picked up in the dispenser the remaining amalgam would become scattered and the dentist would be required to knead the scattered amalgam together, perhaps with fingers, so that the amalgam dispenser could be reloaded. These conditions were not only somewhat unsanitary but perhaps more important gave rise to a tendency for the amalgam to entrain moisture either from the fingers or from atmosphere during the filling operation. Moisture in an amalgam mixture tends to react with certain of the constituents in the amalgam thereby causing a gas to form with the consequent expansion of the filling in the tooth and considerable pain to the patient.

The art of amalgam preparation has been considerably advanced by the development of agitating machines as exemplified by Patents Nos. 2,201,428, 2,286,599 and 2,286,600. In these patents the mortar and pestle combination takes the form of a small capsule into which the mercury and alloy can be deposited, and an agitating element which is placed in the capsule. The capsule is fixed to the ends of a pair of arms which are rapidly vibrated about causing the element within the capsule to agitate the alloy and mercury within the capsule thereby mixing them together to form the amalgam. With this machine the mixing of the amalgam takes no more than one minute.

While the machine has greatly facilitated the mixing operation, it is still necessary for the dentist to scrape the amalgam mixture from the inside of the capsule and to pick it up in small portions in an amalgam dispenser in the manner described above with its consequent disadvantages.

An objective of the present invention has been, in employing a machine of the type described above in mixing amalgam, to provide means for emptying the capsule without the laborious scraping and to place the mixed amalgame in a dispenser ready for application to a tooth without requiring any personal handling of the amalgam and with a minimum exposure of the amalgam to the atmosphere and contamination.

In the preferred form of the invention, the capsule which is agitated by the machine is provided with a valved orifice in one end thereof and a small elongated tube, which projects from the capsule, is attached to the capsule in communication with the orifice. Preferably the tube is provided with a fitting which permits it to be slipped onto the capsule quite readily and which permits it also to be applied to an amalgam dispenser.

We have discovered that after the amalgam has been mixed through the vibration of the capsule by the machine, upon opening of the valve to the orifice, the agitation of the amalgam causes the amalgam, quite unexpectedly, to fiow into the tube projecting from the capsule. The fiow occurs in just a few seconds and in the process almost completely cleans the inside of the capsule.

When the tube has been filled, it can be applied to an amalgam dispenser either on the end thereof for direct introduction into the tooth or as a cartridge placed in the magazine of a dispenser from which it can be expelled for application to a tooth.

Also quite unexpectedly it hs been found that the amalgam which passes from the capsule into the tube has a somewhat higher concentration of mercury at the discharge end of the tube as compared to that of the inlet end of the tube. This is a condition which would be preferred by dentists for it is desirable to have a slightly wetter mixture of amalgam first applied to the tooth. The wetter mixture tends to flow more easily into the small crevices in the tooth. However, after the first application of amalgam to the tooth, it is preferred that the mixture be slightly drier for it is more easily worked, compacted, and sets more rapidly.

It can be appreciated that the invention as described above admits of a number of possibilities or variations, these possibilities forming a portion of the objectives of the invention. For example, it is possible to provide for the automatic sequencing of the mixing of the amalgam, the opening of the capsule valve, the discharge of the amalgam into the tube and the shutting off of the machine. By providing for such automation, the dentist need only place a drop of mercury with an alloy pellet into the capsule, place the capsule on the machine and start the machine. In less than a minute, the tube will automatically be filled and will be ready for application to the amalgam dispenser.

Still another possibility is to employ some receptacle other than the tube to receive the amalgam as it passes through the orifice. Thus the machine could be used by dentists who prefer to pick up and apply a small portion of amalgam at a time. The device would still be advantageous for it would etfect the almost complete cleaning of the capsule which, prior to the advent of the present invention has been a time consuming job for the dentist or his assistant.

In the embodiment of the invention wherein the tube which receives the amalgam is applied to the end of an amalgam dispenser for introduction into the patients mouth, it is possible for the dentist to equip himself with a large number of such tubes which can be sterilized after each use and maintained in a sterilizer until ready for further use.

In developing the present invention, we have improved the agitating qualities of the machine described above by providing a new pestle design comprising a small cylindrical plastic member having a steel core. The plastic member surrounding the steel core provides the proper dimension of pestle and protects the walls of the capsule from the abrading or scoring efiects of the metallic core. A stainless steel core on the other hand provides the necessary weight to the pestle for efficient agitation. In the machine of the type described above which operates at approximately 2,800 r.p.m. by employing the pestle of the present invention the complete mixing and discharging of the amalgam into the tube can be effected in less than twenty seconds. Approximately 15 seconds agitation time is required and three to four seconds is required to discharge the amalgam from the capsule into the tube.

It has been another objective of the invention to provide a tube to receive amalgam, the tube having a slight internal taper which makes the discharge end of the tube slightly larger than the inlet end of the tube.

It has been another objective of the invention to provide a tube of aluminum having its internal surface anodized. We have found that by employing the anodized internal surface of the tube as well as the taper described above, we are able to attain a substantially complete removal of the amalgam during application to a tooth by passing a plunger from the inlet end to the discharge end.

These and other objectives of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view of the complete mixing apparatus;

FIG. 2 is a cross sectional view taken through the center of the capsule and discharge tube;

FIG. 3 is a cross sectional view taken along lines 33 of FIG. 2;

FIG. 4 is a fragmentary end elevational view of the capsule and the arms by which it is retained;

FIG. 5 is a cross sectional view of one form of dispenser with which the invention may be employed;

FIG. 6 is a cross sectional view of another form of dispenser;

FIG. 7 is an elevational view of a cartridge for application to the dispenser of FIG. 6;

FIG. 8 is an alternative form of valve structure for the capsule;

FIG. 9 is across sectional view taken along lines 9-9 of FIG. 8;

FIG. 10 is a cross sectional view of still another valve structure for the capsule;

FIG. 11 is a cross sectional view taken along lines 11--11 of FIG. 10;

FIGS. 12, 13 and 14 are alternative forms of the pestle to be employed within the capsule.

FIG. 15 is a cross sectional view of a capsule having a mixing chamber and a receptacle.

The invention will be described in association with a vibrating machine of the type described in the patents referred to above. It should be understood however that the invention is equally applicable to other types of machines for vibrating the capsule. The machine illustrated in FIG. 1 is mounted on'a base and is driven by a motor 21 which is mounted on the base and which is electrically connected to a 110-volt outlet by an electrical cord 22.

The motor has a shaft 23 which is operably connected to a support 24 for the capsule. The manner in which the support 24 is mounted with respect to the shaft 23 forms no part of the present invention and is adequately described in the patents referred to above. Suffice it to say that in practice the motor tends to drive the support 24 in such a manner that the capsule mounted in the support moves through an elliptical path at a speed of the order of 2,800 r.p.m.

A pair of

resilient arms

25 and 26 form a part of the support and have their upper ends 27 and 23 respectively shaped to receive a capsule 29.

Each end of the capsule is curved and at least the valved end is provided with a projecting key 31. The upper ends 27 and 28 of the arms are similarly curved to receive the ends of the capsule and are provided with key hole slots 32 each having a straight portion 33 which receives the key 31. The cooperation of the key 31 in the straight slot portion 33 prevents the rotation of the capsule with respect to the arm supports and therein maintains the valve lever (to be described below) in proper orientation with the machine in which it is mounted and by which the valve may be automatically actuated.

The capsule and tube are best illustrated in FIG. 2. The capsule is formed of two

halves

35 and 36. The capsule portion 35 has an internal annular shoulder 37 and the capsule portion 36 has an external annular shoulder 33, the two annular shoulders cooperating to provide a male and female fit to place the capsule parts together. A simple friction fit is all that is required to hold the capsule together for the resilience of the supporting

arms

25 and 26 firmly maintains the capsule in closed condition during the mixing and discharging operation.

The capsule provides a generally cylindrical internal mixing chamber 41 which receives a pestle 42 as well as the alloy and mercury which are to be mixed. Thus the internal walls which form the chamber 41 of the capsule serve as a mortar against which the pestle 42 acts to effect the mixing of the alloy and mercury.

The capsule portion 35 has an orifice 45 which is provided with a valve 46 at one end and a nipple 47 at the other end. The nipple 47 has an annular groove 48 which receives an annular lip 49 on a fitting 59 to which the end 51 of the tube 52 is press fitted. Thetube 52 has a discharge end 53 which is normally closed by a plastic cap 54 having an enlarged end portion 55 which facilitates its application and removal.

The preferred form of the valve which will be described in greater detail below is operable by a ring 57 which has a pin 58 projecting therefrom. The pin 58, referring to FIGS. 1 and 4, is engageable by a valve operator 59 slidably mounted on the arm 25 of the vibrating machine. The operator 59 has an abutment 61 projecting therefrom which, when pushed in an upward direction will cause the operator 59 to push the pin 58 in a valve opening direction as explained below.

The abutment 61 is operated by a timer 62. The machine of the patents described above normally is equipped with a 60-second timer which can be set by the dentist with each mixing operation, the timer automatically shutting off the machine at the end of the predetermined length of time. A similar timer is employed in the present invention and has a knob 63 which is rotatable against the action of a spring to set the timer. After the timer has been set, the spring will rotate the knob 63 until the end of the preselected period of time at which time the machine is shut off.

In the present invention a rod 64 is mounted on the timer knob 63 and extends therefrom to a position immediately adjacent the abutment 61. In normal operation, as the arms vibrate left and right as viewed in FIG. 1, the end 65 of the rod 64 will remain out of engagement with the abutment 61. The end 65 of the rod however is provided with a projection 66 which, when rotated to an uppermost position near the end of the vibrating period will be engaged by the abutment 61 and, in one vibrating stroke will force the valve operator 59 in an upward direction to open the valve. The position of the projection 66 with respect to the timer and the abutment 61 will be such as to open the valve of the machine approximately 3 /2 seconds prior to the end of the vibrating period. It has been found that on the particular machine with which the invention is used this period of time is long enough to effect the discharge of the amalgam from the inside of the capsule into the tube 52 but is not long enough to effect too great a compacting of the amalgam within the tube. It should be understood of course that the time period is variable depending upon the particular type of vibrating machine, the shape of the capsule and the weight and shape of the pestle.

The receptacle into which the amalgam is discharged through the orifice 45 of the capsule 29 may take any one of a variety of forms. For example, it could be any shaped receptacle desired by the particular dentist. Such a receptacle is shown at 67 in FIG. 15. It might also be simply a squeeze bag which is commonly employed by a dentist in the preparation and use of amalgam. It might be a straight tube as illustrated at 68 in FIG. 7 which can be used as a dispenser spout or preferably in a magazine type dispenser of the type to be described below in connection with FIG. 6. In one form of the invention the receptacle is the tube 52 which has a curved configuration to make it most adaptable for the direct application of amalgam to a tooth in the patients mouth.

The tube of this embodiment is formed in four principal steps. First, the tube is made of drawn aluminum having .089 inch inside diameter which is cut to a length of approximately 1% inches.

Second, this tube is spun on a tapered mandrel to taper the inside diameter so that upon completion of the tube the inside diameter tapers uniformly from .090 inch diameter at the inlet end to .100 inch diameter at the discharge end. The tube thus has a length slightly greater than fifteen times its internal diameter. Its internal diameter has a .010 inch taper from one end to the other.

In the third step, a nylon core is inserted in the tube and the tube is bent to the configuration shown in FIGS. 1 and 2. Thereafter in the fourth step, the tube is subjected to an anodizing operation to provide as smooth an internal finish as possible. It has been found that the anodized aluminum surface best resists the adherence of the amalgam and as a consequence permits the easy expelling of the amalgam into the patients tooth.

The nylon fitting 50 (FIG. 2) is press fitted onto the inlet end 51 of the tube 52. The fitting has an enlarged diameter at the central portion thereof in order to give it sufficient strength to resist the force which the dentist applies when placing amalgam into the tooth. The nylon has sufiicient resilience to permit the opening defined by the lip 48 to expand and slide over the end of the nipple 47 until the lip 48 is captured in the annular groove 49 of the nipple. As can be seen by referring to FIG. 1, the end portion of the fitting 50 adjacent the lip 48 is split so as to facilitate the application and removal of the fitting from the nipple 47. It should be understood that other materials such as plastics might be used for the tube 52 and fitting 50. Perhaps disposable dispening tubes might be employed.

Valve 46 admits of a variety of forms some of which are illustrated herein. However, the preferred form of the valve is as illustrated in FIGS. 2 and 3. As shown in FIGS. 2 and 3, the orifice 45 has its inlet end portion bored to provide a first annular shoulder 75 and a second annular shoulder 76. The shoulders receive a resilient plastic T-shaped member 77 which is fixed at its larger end 78 in the recess defined by the shoulder 75. A pair of pins 79 are slidably mounted in radial bores and have their ends 80 in engagement with the resilient flexible sleeve 77. The outer ends of the pins 79 are received in recesses 82 in the ring 57. The recesses are shaped to provide cam surfaces which bear against the outer ends 81 of the pins, the ends 81 acting as cam followers. As viewed in FIG. 3, when the ring 57 is rotated in a clockwise direction, the cam surfaces of recesses 82 force the pins radially inwardly to squeeze the opening 83 of the sleeve 77 closed. On the other hand, when the ring 57 is rotated counterclockwise, that is, by the pin 58 being forced upwardly by the operator 59, the resilience of the sleeve 83 forces the pins radially outwardly thereby opening the hole 83 in the sleeve and permitting the passage of amalgam from the capsule to tube 52.

The use of the resilient sleeve 77 tends to shield the valve operating mechanism from the amalgam as it passes from capsule to tube and thereby increases the useful life of a capsule.

Another type valve is shown in FIGS. 8 and 9. That valve is a form of gate valve having a slidable plate 85 mounted in a transverse slot through the center of the end portion of the capsule. In a lower position as illustrated 6 in FIG. 9, the slidable plate is across the orifice and does not permit the passage of the amalgam. When the plate 85 is moved upwardly as viewed in FIG. 9, it brings an opening 86 into alignment with the orifice 45 thereby permitting the passage of the amalgam.

The plate 85 is slotted at each end as indicated at 87. The slot leaves a strip 88 which is bent beyond its elastic limit to a position illustrated at 89. The material of the plate 85 is resilient so that each portion 88 forms a spring which tends to fix the member 85 either in the upper open position or lower closed position shown. Thus the plate 85 cannot be inadvertently vibrated to the open position during the operation of the machine.

Still another form of valve is illustrated in FIGS. 10 and 11. There the valve is simply a cylindrical element extending diametrically across the orifice 45. The element 91 has a transverse passageway 92 extending therethrough. A crank handle 93 engageable by operator 59 is turned to effect the opening and closing of the valve. In the downward position of the crank handle 93, the valve is closed as illustrated. When the crank handle 93 is swung upwardly through an angle of the passageway 92 is brought into alignment with the orifice 45 thereby opening the valve.

In the several valve embodiments described, the valve has been shown as mounted in the capsule. It should be understood that other variations are possible which are within the scope of the invention. For example, a valve mechanism could be built into the vibrating machine 21 as for example by mounting it on the arm 25. The arm 25 would have a fitting to receive the tube 52 on one side thereof and a fitting to receive the open end of a capsule on the other end thereof, the valve being disposed between the two ends of the fitting. Alternatively, a tube which is flexible in whole or in part could be associated with a squeeze clamp which could provide a valve action in the tube itself merely by collapsing the tube to close communication between the capsule and a tube. The important consideration is that there be a capsule within which the material is agitated and mixed, a receptacle into which the mixed amalgam may be driven and a valve selectively blocking and thereafter admitting passage of amalgam from the capsule to the receptacle. It should also be understood that while the preferred form of the invention provides for automatic actuation of the valve, manual actuation of the valve is possible with any of the valves illustrated and/or described.

A number of forms of the pestle are contemplated. The preferred form is shown in FIG. 14 and comprises simply a nylon or other suitable plastic sleeve 95 which is press fitted on a stainless steel core having a knurled surface 96. The nylon sleeve prevents any contact of the internal walls of the capsule by the stainless steel core and thereby preserves the smooth interior of the capsule which is important to itself-cleaning action. The stainless steel core on the other hand is important in order to give the pestle the proper weight for eflicient agitating and mixing action. Preferably, the combined weight of the nylon and steel is twenty grains. While the dimensions and weight admit of considerable variation, it has been found that a completely satisfactory operation is effected by a pestle which is of 0.314 inch diameter and 0.360 inch long, the pestle operating in a capsule which is /8 inch in internal diameter and approximately 1 inch long. The steel core is 0.160 inch in diameter.

Alternatively the pestle may be formed as shown in FIG. 13 in which a steel ball 97 is completely surrounded by nylon as at 98, the ball being closed within the nylon by a cap 99. Similarly instead of a steel ball, steel shot 101 may be employed as shown in the embodiment of FIG. 12. There the steel shot is deposited in a cavity formed in a nylon member 102 and enclosed by a cap 103. Also a pestle of the size and weight described above may be manufactured from metal by boring a metal member of the proper size until its weight is reduced to twenty grains and capping the hole.

When the amalgam has been discharged into a tube 52, the tube 52 can be removed and attached to an amalgam dispenser as shown in FIG. which has an elongated sleeve 104 in which a rod 105 having a fiat top 106 is slidably mounted. The dispenser has a discharge end 107 provided with a small bore 108 in which a thin nylon rod 109 is slidably mounted. The dimensions of the bore 108 and nylon rod 109 should be approximately the same. The end 107 terminates in a nipple 110 and locking sleeve 111. The nipple 110 and locking sleeve 111 are adapted to receive the fitting 50 at the end of the tube .52, the sleeve 111 having an internal taper adapted to slide over the fitting and press it onto the nipple to avoid its inadvertent dislocation.

A pair of finger grips 112 project from the sides of the sleeve 104 to permit the dispenser to be held between the fingers, on the elements 112 and the thumb on the flat top 106. The nylon rod 109 serves as a plunger and its diameter should be substantially the same as the internal diameter of the tube 52 .so that it can completely expel all the amalgam deposited in the tube through the action of the vibrating machine.

Alternatively the amalgam dispenser may be a breech loading type. Such a dispenser is illustrated in FIG. 6 with the cartridge for employment with the dispenser being illustrated at 68 in FIG. 7. A sleeve 115 is provided with a slidable rod 116, the rod having a nylon plunger rod 117 attached to one end thereof. A dispensing spout 118 is provided at the end of the dispenser and a breech 119 is located between the dispensing spout 118 and the sleeve 115. The breech has a pair of spring clips 120 which resiliently grip the cartridge 68 between them to position the discharge end 121 of the cartridge immediately adjacent the spout 118 and the fitting end 122 immediately adjacent the sleeve 115. The plunger rod 117 is adapted to be completely withdrawn to permit the application of the cartridge 68 to the breech of the dispenser. Thereafter the operation is similar to that described in connection with the dispenser of FIG. 5 wherein the rod 116 is pushed by the thumb of the dentist to cause the nylon plunger 117 to pass through the tube 68 and to expel the amalgam therein from the tube 68 into and out of the dispensing spout 118.

Operation In the operation of the invention the dentist places a drop of mercury in the bottom of a capsule portion 36, places the pestle over the mercury and then places a pellet of alloy above the pestle. Of course the capsule can receive two pellets and two drops of mercury to provide a double charge. The tube of the size described above is exactly dimensioned to receive a double charge of amalgam.

After the capsule portion 36 has been loaded as described, it is attached to the other capsule portion 35 and the assembly placed between the

arms

25 and 26 of the vibrating machine. The valve 46 at this stage should be closed to prevent the inadvertent egress of the unmixed mercury or alloy during the operation. In positioning the capsule on the

arms

25, 26, the key projections 31 should be aligned with their appropriate key slots so as to avoid the rotation of the capsule during vibration.

When the capsule has been positioned with the valve closed in the machine, the timer is set for operation. Preferably approximately fifteen seconds of agitation time is employed. At the end of the agitation period, the projection 66 on the rod 64 will have rotated until it is engageable by the abutments 61 on the slidable operator 59. Upon engagement, the operator 59 slides upwardly and rotates the valve to open position.

It should be understood that automatic operation is not essential to the invention although it is preferred for the sake of convenience. If the automatic operation of the valve has not been provided for, the machine may simply be shut down until the dentist can rotate the valve manually to open position. Thereafter the machine should be started up again and set for approximately 3 /2 seconds vibration.

Whether automatic or manual, 3 /2 seconds vibration with the valve open is preferred in order to effect the substantially complete cleaning of the interior of the capsule and the discharge of all of the amalgam into the discharge tube 52. It should be noted that the particular pin actuated sleeve type valve illustrated in FIGS. 2 and 3 will not permit any amalgam to enter the valve operating mechanism and to clog it.

When the discharge tube has been completely filled, it is removed from the capsule merely by pulling it off the nipple 47. The tube is then snapped onto the dispenser illustrated in FIG. 5 and the cap 54 removed. When these steps are taken the amalgam is ready for application into the tooth of the patient. As the amalgam is being applied to the tooth of the patient, the tapered or flaring tube 52 permits the easy discharge of the amalgam into the tooth.

It can be appreciated from the foregoing that the constituents of the amalgam are not exposed to human hands or to atmosphere from the time that they are placed in the capsule until they are discharged into the patients mouth. It should also be appreciated that the tedious picking up of amalgam into a dispenser portion by portion has been eliminated.

The operation has been described in connection with the curved type tube. Ina similar manner, the straight cartridge tube of FIG. 7 would be filled, the cap removed and the tubepositioned in the breech loading dispenser of FIG. 6.

We claim:

1. Apparatus for loading amalgam into a tube comprising, a mixing chamberhaving an orifice, agitating means in said mixing chamber, an elongated tube mounted on said mixing chamber at said orifice, said tube having an inlet end adjacent said orifice and a discharge end, said tube having a gradually increased inside diameter from said inlet end to said discharge end, and a valve in said orificebetween said mixing chamber and said tube.

2. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice, agitating means in said mixing chamber, an elongated tube mounted at one end on said mixing chamber at said orifice, said tube and orifice having substantially the same diameter, a valve in said orifice between said mixing chamber and said tube, and a removable stopper positioned in the other end of said tube.

3. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice, agitating means in said mixing chamber, a tube mounted on said mixing chamber at said orifice, said tube being of aluminum and having its internal surface anodized, said tube and orifice having substantially the same diameter, and a valve in said orifice between said mixing chamber and said tube.

4. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice, agitating means in said mixing chamber, a tube mounted on said mixing chamber at said orifice, a valve in said orifice between said mixing chamber and said tube, said tube being approximately one and five-eighths inches long and having an inside diameter of approximately 0.090 inch, said diameter increasing 0.010 inch from one end adjacent said orifice to the other.

5. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice terminating in a projecting nipple, said nipple having an annular groove in the external surface thereof, agitating means in said mixing chamber, a tube mounted on said mixing chamber at said orifice, said tube and orifice having substantially the same diameter, a resilient fitting on one end of said tube, said fitting having an internal lip cooperable with the groove on said nipple to secure said tube on said nipple, and a valve in said orifice between said mixing chamber and said tube.

6. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice, agitating means in said mixing chamber, a'tube whose length is approximatelyfifteen times its average internal diameter, means removably mounting said tube on said mixing chamber at said orifice, and a valve in said orifice between said mixing chamber and said tube.

7. Apparatus for loading amalgam into a tube comprising, a mixing chamber having an orifice, agitating means in said mixing chamber, a tube mounted on said mixing chamber at said orifice, said tube and orifice having substantially the same diameters, said tube being curved and adapted to be mounted at the discharge end of an amalgam dispenser, and a valve in said orifice between said mixing chamber and said tube.

8. Apparatus for the preparation of amalgam com prising, a motor, a support, transmission means connecting said motor to said support to vibrate said support, a capsule having a hollow mixing chamber removably mounted on said support, said capsule having an orifice, agitating means in said mixing chamber, a receptacle mounted on said mixing chamber in said orifice, a valve in said orifice between said mixing chamber and said receptacle, an operating lever projecting from said capsule and connected to said valve to open and close same, a timer, and means on said timer operably engageable by said valve lever to operate said valve after a preselected interval of operation.

9. Apparatus for the preparation of amalgam comprising, a motor, a support, transmission means connect ing said motor to said support to vibrate said support, a capsule having a hollow mixing chamber removably mounted on said support, said capsule having an orifice, agitating means in said mixing chamber, a receptacle mounted on said mixing chamber in said orifice, a valve on said orfice between said mixing chamber and said receptacle, an operating lever projecting from said capsule and connected to said valve to open and close same, and means connected to said valve for automatically opening said valve after an interval of operation.

10. Apparatus for the preparation of amalgam comprising, a motor, a support, transmission means connecting said motor to said support to vibrate said support, a capsule having a hollow mixing chamber removably mounted on said support, said capsule having an orifice, agitating means in said mixing chamber, a receptacle mounted on said mixing chamber in said orifice, a valve in said orfice between said mixing chamber and said receptacle, an operating lever projecting from said capsule and connected to said valve to open and close same, a timer operably associated with said valve and said motor to effect vibration of said capsule for a first period with said valve closed and thereafter to open said valve and effect vibration of said capsule for a second period of time until said capsule has emptied into said receptacle.

11. Apparatus for the preparation of amalgam comprising, a motor, a support including a pair of resilient arms, transmission means connecting said motor to said support to vibrate said support, a capsule having a hollow mixing chamber removably mounted between the ends of said arms, said capsule having an orifice, agitating means in said mixing chamber, a receptacle mounted on said mixing chamber in said orifice, a valve in said orifice between said mixing chamber and said receptacle, and operating lever projecting from said capsule and connected to said valve to open and close same, abutment means slidably mounted on one of said arms and engageable with said operating lever, a timer, and means on said timer operably engageable by said abutment means efiect operation of said valve after a preselected interval of operation.

12. Apparatus for loading amalgam into a tube comprising,

a mixing chamber closed at its ends, one of said ends having a small orifice,

a pestle in said mixing chamber for mixing amalgam and driving it through said orifice,

an elongated tube having a smooth unrestricted internal bore of substantially uniform diameter throughout its length and having openings only at its ends, said openings being substantially the same diameter, said tube being mounted on said mixing chamber at said orifice,

and a valve in said orifice between said mixing chamber and said tube whereby said tube is adapted to receive a plunger for passage therethrough to expel amalgam.

13. Apparatus for loading amalgam into a tube comprising,

a cylindrical mixing chamber having an orfice less than half the diameter of said chamber,

a tube mounted on said mixing chamber at said orifice,

a cylindrical pestle for mix-ing and driving amalgam into said tube, said pestle being composed of a metallic core and a plastic jacket around said core, the diameter of said pestle being greater than onehalf the inside diameter of the capsule,

and a valve in said orifice between said mixing chamber and said tube.

14. Apparatus for the loading of amalgam into a tube comprising,

a motor,

a support,

transmission means connecting said motor to said support to vibrate said support,

a capsule having a hollow mixing chamber removably mounted on said support,

said capsule having a small orifice,

an elongated tube mounted on said mixing chamber at said orifice, said tube and orifice having approximately the same diameter,

a valve in said orifice between said mixing chamber and said receptacle,

an operating lever projecting from said capsule and connected to said valve to open and close same,

and a pestle in said mixing chamber for mixing amalgam and driving it through said orifice through the vibration of said capsule by the motor and support upon opening of said valve.

15. Apparatus for loading amalgam into a tube comprising,

a mixing chamber closed at its ends, one of said ends having a small orifice,

an elongated gradually curved tube having a smooth unrestricted internal bore of substantially uniform diameter throughout its length and having openings only at its ends, said openings being substantially the same diameter, said tube being mounted on said mixing chamber at said orifice,

References Cited by the Examiner UNITED STATES PATENTS 833,044 10/1906 Goodhugh 32-60 1,464,700 8/1923 Feust 241-184 1,494,809 5/1924 Sahr 128-232 1,524,662 2/ 1925 Layman 222-561 1,686,135 10/1928 Hurdle 259-75 (Other references on following page) 1 1 1 2 Barton 128-234 2,903,794 9/1959 Carfagni 3260 .Ch'ne 222554'XR 3,034,735 5/ 19612 Cadwell 241184 Lomas 222554 Chou 259 72 FOREIGN PATENTS Eubanks 20 47 5 499,727 11/ 1954 Italy. Greenberg 259 72 611,192 12/1960 Canada. Greenberg 22 2 5 XR 804,824 11/1958 Great Britain. C h 128261 XR g gg XR CHARLES A. WILLMUTH, Primary Examiner. Bell 64-4 1 LEO QUACKENBUSH, Examiner.

Claims

2. APPARATUS FOR LOADING AMALGAM INTO A TUBE COMPRISING, A MIXING CHAMBER HAVING AN ORIFICE, AGITATING MEANS IN SAID MIXING CHAMBER, AN ELONGATED TUBE MOUNTED AT ONE END ON SAID MIXING CHAMBER AT SAID ORIFICE, SAID TUBE AND ORIFICE HAVING SUBSTANTIALLY THE SAME DIAMETER, A VALVE IN SAID ORIFICE BETWEEN SAID MIXING CHAMBER AND SAID TUBE, AND A REMOVABLE STOPPER POSITIONED IN THE OTHER END OF THE SAID TUBE.