US2760268A - Device for expelling mercury and the like from amalgam - Google Patents

Description

28, 1956 J. w. RICHARDS ETAL 2,760,268

DEVICE FOR EXPELLING MERCURY AND THE LIKE FROM AMALGAM Filed Aug. 51, 1955 INVENTO am di CZeZZa/z United States Patent DEVICE FOR EXIELLING lVlERCURY AND THE LIKE FROM AMALGAM John W. Richards and Wayne L. McClellan, Ottumwa, Iowa Application August 31, 1953, Serial No. 377,532

14 Claims. (Cl. 32-40) This invention relates to a dental tool or appliance useful in the expelling of mercury and the like from amalgam for preparing so-called silver fillings.

Silver amalgam as used in the dental profession is composed of mercury and silver alloy. These two materials are amalgamated by means of a triturating action through the use of high-speed vibration or by means of hand trituration with a mortar and pestle. Silver alloy is an inert powdered mass until amalgamated with mercury. This amalgamation produces a plastic mass in which the mercury serves as a catalytic agent. After the mercury has served its catalytic function it must be expelled from the amalgam before the necessary crystallization can occur. The more mercury that is removed, the stronger the filling. The process of expelling mercury is known as drying. At the present time, drying is accomplished by placing the amalgam in a small cloth pouch, and the pouch is squeezed and rolled between the thumb and forefinger or between simple pliers until mercury has been expelled from the amalgam in an amount consistent with the efiiciency of the methods employed. The finger-pressure method is tiresome and labo-v rious. The plier method produces only a static pressure and is therefore relatively inetficient. According to the present invention, a tool is designed to mechanically expel mercury from the amalgam more efiiciently and thoroughly by means of a kneading action or the like, specifically employing spring-loaded levers for actuating a kneading member or roller against a shoe or anvil, the cloth pouch containing the amalgamknown as a dental clothbeing received between the roller and shoe. The tool difiers from a simple pair of pliers in that the pressure applied to the roller or equivalent kneading member is dynamic rather than static and the spring loading enables rolling or kneading in opposite directions in response to alternate application and release of force to the actuating members, which members are, in a simple and preferred case, handles capable of being gripped in one hand of the user.

It is a principal object of the invention to provide such tool in a simple and inexpensive form, and one that has relatively few moving parts so that it has the characteristic of long life and efliciency. It is an important object of the invention to construct a tool that will play an important role in the production of fillings of substantially higher quality because of the ability of the tool to expel a higher percentage of mercury than is possible by previously known methods. A still further important feature of the invention resides in the arrangement of the linkage or lever means in conjunction with a spring so that movement of the roller or kneading member against the shoe or anvil is accompanied by a progressively increasing pressure of the roller in one direction and conversely a decreasing pressure as the roller moves in the opposite direction. When this principle is utilized in a plier-like instrument, the alternate application and relaxation of manual force to the handle will cause the roller Patented Aug. 28, 1956 to roll or rock back and forth to impart a kneading action thereto which is instrumental in expelling the maximum percentage of mercury from the amalgam. Another object of the invention is to provide the shoe or anvil with a roughened area to constitute anti-skid means for preventing displacement of the amalgam while it is subjected to the squeezing or kneading action.

The foregoing and other important objects and desirable features inherent in and encompassed by the invention will become apparent to those versed in the art as a preferred embodiment of the invention is fully disclosed in the following detailed description and accompanying sheet of drawings in which Fig. 1 is a perspective view of the tool or appliance.

Fig. 2 is a fragmentary sectional view, as seen substantially along the line 2-2 of Fig. l, and showing the roller or kneading member in one position.

Fig. 3 is a transverse sectional view as seen substantially along the line 3--3 of Fig. 2.

Fig. 4 is a sectional view similar to Fig. 2 but showing the parts in diflerent positions.

Reference will be had first to Fig. 1 for an over-all explanation of the device. As seen in that figure, the tool or device comprises first and second elongated elements, designated generally by the numerals 10 and 12 respectively. The element 10 is of such nature as to inciude integrally therewith an upper handle or force-receiving means 14 and a lower jaw or arm 16 having an upper surface 18 that establishes a ramp or track means. The elements 19 and 12 are crossed and are pivotally interconnected intermediate their ends as by pivot means including a pivot pin 20 so that the element 12 includes a lower handle or force-receiving means 22 disposed below the handle 14 and an upper arm or jaw 24 disposed above the lower jaw or track 16.

Here, as well as in the claims, reference to the tool as having upper, lower, etc. parts is solely for convenience and is not designed to impart any limitations into the spirit of the invention.

In the preferred embodiment of the invention illustrated, the arrangement of the elements 10 and 12 in crossed and pivotally interconnected form provides generally a plier association of the parts, so that squeezing of the handles 14 and 22 together causes the jaws or arms 16 and 24 to move together. Conversely, when the handles 14 and 22 are spread apart, the jaws 16 and 24 move apart. The upper arm or jaw 24 has a terminal end portion 26 that naturally moves in an are about the pivot pin 20 as it travels alternately toward and away from the track 18 on the lower jaw or shoe 16. A link or lever 28 has an upper end 30 pivotally connected to the terminal end 26 of the upper arm or jaw 24 by means of a pivot pin 32, the axis of which is parallel to the pivot or fulcrum axis 20. The lever 30 has a bifurcated lower end 34 between the furcations of which is disposed a kneading or rocking member in the form of a roller 36. This roller preferably comprises a small sealed ball bearing having inner and outer races and journaled in the lower end 34 of the link 28 by means of a shaft or pin 38 that establishes a rolling axis parallel to the axes at 20 and 32. The link 28 .and roller 36 may be said to constitute movable kneading or roller means carried by the support established by the upper arm or jaw 24. Intermediate its ends, the link or lever 28 has an apertured web portion 40 (Figs. 2, 3, and 4) into which is hooked one end 42 of biasing or energy-storing means, here in the form of a coiled tension spring 44, the other hooked end 46 of which is connected to at least one of the elements 10 or 12 by means of being hooked about the fulcrum or pivot pin 20.

Because of the plier form of the tool, the handles 14 and 22 are at one side of the pivot axis 20 and are respectively above and below a horizontal plane, for example, passed through that axis. Likewise, the jaws or arms 16 and 24 are at the other side of the pivot axls and are respectively above and below such plane. The track 18 provided on the paw or arm 16 is here shown as being in the form of a ramp or slope that is directed downwardly and away from the pivot or fulcrum axis 20 tion, the spring 44 is stretched or additionally loaded and the energy stored therein serves not only to improve the kneading action but to return the roller to its initial position. Consequently, the upper arm or support 24 and the link or lever 28 comprise first and second levers in a link means capable of imparting a rocking or kneading action to the roller 36 in response to forces applied to and released from the force-receiving means comprising the handles 14 and 22. In the case of a manual tool, as illustrated, release of pressure or force on the handles is accompanied by return of the roller 36 to its initial position, the spring 44 serving at the same time to open the handles so that they may be again squeezed together. Consequently, alternately squeezing and releasing the handles causes the roller or pressure member 36 to rock or roll back and forth along the inclined shoe or ramp provided by the track 18.

The motion resulting from operation as just described is used to expel mercury and the like from amalgam received by the track or shoe 18. As previously stated, it is conventional to utilize what is known as a dental cloth for containing the amalgam. In the profession, such dental cloth is approximately three inches in diameter and is placed in the palm of the hand and a pellet of amalgam is placed in the center of the cloth. The cloth is then gathered together in pouch form and the operator holds the loose ends of this pouch in his left hand and grasps the handles 14 and 22 of the tool in his right hand (or vice versa if he so desires). Such pouch is not shown in detail in the drawings, since it is conventional and its use in the finger-pressure or plier method is well known. However, for purposes of illushating the present invention, the pellet-containing portion of the pouch is designated by the letter P and is shown in dotted lines in Figs. 2 and 4. In Fig. 4 the pouch has been flattened as part of the kneading or rocking process.

As shown in Fig. 1, the upper surface of the anvil, track or shoe has a portion of its area roughened, as by being lightly knurled, as at 48, to provide what may be called anti-skid means for preventing displacement of the amalgam-containing pouch.

It will be apparent from the foregoing description that the tool or device, as reduced to its substantially simplest form in the present disclosure, may be easily operated by manual pressure alternately applied to and released from the handles 14 and 22. Force applied to the handles causes the link 28 and roller 36 to be driven forwardly or outwardly over the sloping track or ramp, whereupon the roller 36 rocks or rolls over the amalgam and the spring 44 is stretched, which is represented sub stantially by the change in positions of the parts between Figs. 2 and 4. Release of pressure or force on the handles 14 and 22 allows the spring to retract the pressure or kneading means comprising the link 28 and roller 36 for rocking or rolling the roller 36 in the opposite direction. Thus, not only is a downward pressure applied to the kneading means but a motion is transmitted A thereto that causes it to rock or roll in one direction with a progressively increasing dynamic pressure as opposed to a static pressure. The energy stored in the spring produces a dynamic force as the roller 36 is drawn back uphill when pressure on the handles 14 and 22 is relaxed. Although the ramp or track 18 is shown as being a curve concave as respects the pivotal connection 32, it may be straight or any other shape. Fig. 3 shows that the track 18, as viewed from the end or in transverse section, is fiat; although, the shape could vary according to individual desires, as could the shape of the roller 36 to correspond with the selected shape of the track 18. Based on present experiences, the track 18 is a relatively long gentle curve arranged in progressively increasing spaced relation to the terminal end portion 26 of the arm or support 24. Stated broadly, the invention appears to reside in the pair of opposed jaw-like elements 7 interconnected for relative movement toward and away from each other, together with the rocking or pressure member interposed therebetween and arranged to cooperate with one of the jaw elements to knead or roll over the amalgam carried by that one jaw, including force-transmitting means connected between the rolling or pressure means and one of theelement-s for causing the roller or pressure means to roll back and forth in response to movement of the elements relative to each other, thus producing a dynamic pressure, as aforesaid, as opposed to a static pressure resulting from simply squeezing the amalgam.

Other features of the invention not specifically enumerated herein will undoubtedly occur to those versed in the art, as likewise will numerous modifications and alterations in the preferred embodiment of the invention, all of which may be achieved without departing from the spirit and scope of the invention.

What is claimed is:

1. A tool of the character described, comprising: first and second elongated elements arranged in plier relationship and pivotally interconnected intermediate their ends on an axis transverse to their length to provide, on the first element, an upper handle and a lower anvil respectively at opposite sides of the pivot axis and, on the second element, a lower handle and an upper arm respectively at opposite sides of said pivot axis so that said lower handle is normally spaced below the upper handle and the arm is normally spaced above the anvil; said arm having a terminal end portion movable toward and away from the anvil on an are about the pivot axis when the handles are moved respectively toward and away from each other; said anvil being of such length as to have a terminal end portion beyond said are and further having an upper surface sloping downwardly and away from the pivot axis in progressively increasing spaced relation to the terminal end portion of the arm; roller means arranged to roll along the anvil upper surface between a starting position adjacent to the pivot axis and a second position adjacent to the terminal end portion of the anvil for rolling back and forth over a substance or object placed on the anvil upper surface; lever means having an upper end rockably connected to the terminal end portion of the arm on an axis parallel to the pivot axis and a lower end connected to the roller means on the rolling axis of the roller means for moving the means from its starting position toward its second position when the handles are moved toward each other; and yielding means connected between the lever and one of the elements for biasing the lever toward the pivot axis so as to bias the roller means to its starting position. Y

Y 2. The invention defined in claim 1, in which: the upper anvil surface has at least a portion of its area roughened to provide anti-skid means for the substance or object placed thereon to be rolled over by the roller means.

3. The invention defined in claim 1, in which: the yielding means comprises a tension spring; the pivotal interconnection of the elements includes a pivot pin; and

the spring is connected at one end to the lever and at its other end to the pivot pin.

4. The invention defined in clan'n 1, in which: the upper anvil surface is a relatively long gentle curve concave as respects the terminal end portion of the arm.

5. A tool of the character described comprising: first and second elongated elements arranged in plier relationship and pivotally interconnected intermediate their ends on an axis transverse to their length to provide, on the first element, an upper handle and a lower anvil respectively at opposite sides of the pivot axis and, on the second element, a lower handle and an upper arm respectively at opposite sides of said pivot axis so that said lower handle is normally spaced below the upper handle and the arm is normally spaced above the anvil; said anvil having an upper surface running lengthwise below the arm and adapted to receive thereon a substance or object to be subjected to pressure; said arm having a terminal end portion movable toward and away from the anvil surface on an are about the pivot axis as the handles are moved toward and away from each other; kneading means positioned between the terminal end portion of the arm and the anvil upper surface to contact such substance or object on said surface; and motiontransmitting means connecting the kneading means to the upper arm for applying downward pressure on the kneading means and simultaneously moving the kneading means back and forth along the anvil upper surface.

6. A dental tool for expelling mercury and the like from amalgam, comprising: anvil means having a surface on which the amalgam is placed; kneading means cooperative with the anvil surface to engage the amalgam; means connecting the kneading means to the anvil means for imparting a rocking action to the kneading means; and means connected to the kneading means and to the anvil means for applying to the kneading means, substantially simultaneously with said rocking action, a pressure directed toward the anvil surface.

7. The invention defined in claim 6, in which: the anvil surface has at least a portion of its area roughened to provide anti-skid means for restraining the amalgam against displacement as it is kneaded.

8. A dental tool for expelling mercury and the like rom amalgam, comprising: anvil means having a surface on which the amalgam is placed; lever means fulcrurned on the anvil means and including force-receiving means to effect movement thereof toward and away from the anvil surface; kneading means cooperative \m'th the anvil surface to engage the amalgam on said surface; means interconnecting the lever means and the kneading means for moving the kneading means back and forth over the surface-carried amalgam in opposite directions of movement of the lever means; and yielding means connected between the kneading means and the anvil means for biasing the kneading means into intimate contact with the amalgam as said kneading means is moved back and forth as aforesaid.

9. A dental tool for expelling mercury and the like from amalgam, comprising: a pair of opposed jaw-like elements interconnected for relative movement toward and away from each other, one of said elements having thereon and opposed to the other of said elements a surface for carrying amalgam; rolling means interposed between the elements and arranged to engage the elementcarried amalgam; means respectively on the elements for moving them relatively toward and away from each other; and force-transmitting means connected between the rolling means and one of the elements for causing the rolling means to roll back and forth over the element-carried amalgam in response to movement of the elements relative to each other.

10. A dental tool for expelling mercury and the like from amalgam, comprising: a pair of elements interconnected for relative movement and including opposed handles for receiving manual force and opposed arms movable alternately toward and away from each other in response to the alternate application and release of such manual force; means on one arm for carrying amalgam; a pressure member cooperative with said means and engageable with amalgam carried by said means; means connecting the pressure member to one of the elements for pressing said member toward the amalgam-carrying means and simultaneously rocking said member in one direction in response to force applied to the handles; and energy-storing means connected to the pressure member and to one of the elements and loaded upon said rocking of the pressure member for pressing said member toward the amalgam-carrying means and simultaneously rocking said member in the opposite direction upon release of force from the handles.

11. A dental tool for expelling mercury and the like from amalgam, comprising: a pair of elongated elements interconnected for relative movement and including opposed handles for receiving manual force and opposed arms movable alternately toward and away from each other in response to the alternate application and release of such manual force; means on one arm for carrying amalgam including a track running lengthwise of said one arm and opposed to the other arm; a roller cooperative with said track means and engageable with amalgam carried thereby; means connecting the roller to one of the elements for pressing said roller toward the track means and simultaneously causing said roller to roll in one direction in response to force applied to the handles; and energy-storing means connected to the roller and to one of the elements and loaded upon said rocking of the pressure member for pressing said roller toward the track means and simultaneously causing the roller to roll in the opposite direction upon release of force from the handles.

12. The invention defined in claim 11, in which: the track means has a roughened surface portion preventing displacement of the amalgam .as the roller is caused to roll back and forth.

13. A dental tool for expelling mercury from amal garn, comprising: anvil means having a surface adapted to receive amalgam thereon to be subjected to pressure; kneading means arranged proximate to the anvil means surface to contact such amalgam; and movable along said surface to squeeze the amalgam; means connected respectively to the anvil means and to the kneading means for receiving force; and force-transmitting means connected to the force-receiving means and to the kneading means for applying a progressively increasing force to the kneading means and thus to produce a dynamic kneading pressure on the amalgam.

14. A dental tool for expelling mercury from amalgam, comprising: anvil means having a surface adapted to receive amalgam thereon; pressure means cooperative with the anvil means to squeeze such amalgam against the anvil means; lever means interconnecting the anvil means and the pressure means for moving the two relatively, said lever means including a first lever pivoted to the anvil means and a second lever pivoted to the first lever and additionally pivoted to the pressure means; spring means interconnecting the first and second levers and exerting an initial force pressing the pressure means against the amalgam on the anvil means surface to apply an initial squeezing pressure thereon; and forcereceiving means connected to the lever means for moving the levers relatively against the spring means to progressively increase the load on the spring means and thereby to progressively increase the pressure applied by the pressure means.

References Cited in the file of this patent UNITED STATES PATENTS 770,162 Chase Sept. 13, 1904 1,262,621 Beacha-m Apr. 16, 1918 2,399,834 Seltzer May 7, 1946

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