US2669780A - Pin centering and paralleling instrument - Google Patents

Description

Feb. 23, 1954 w MANN 2,669,780

PIN CENTERING AND PARALLELING INSTRUMENT Filed Feb. 5, 1953 2 Sheets-Sheet l Arvin W. Mann IN VEN TOR.

Feb. 23, 1954 A. W. MANN PIN CENTERING AND PARALLELING INSTRUMENT Filed Feb. 5, 1953 2 Sheets-Sheet 2 Fig. .9

6 80 lllllll g Fig. 6

g. 7 I QIIIEWQ a0 Arvin W. Mann INVEN'TOR.

BY WWW E Attorney:

Patented Feb. 23, 1954 PIN CENTERING AND PARALLELING INSTRUMENT Arvin W. Mann, Fort Lauderdale, Fla. Application February 5, 1953, Serial No. 335,285

9 Claims.

This invention relates to restorative dentistry and more particularly to a device especially adapted for use in obtaining a hard cast or model from an elastic impression in which the individual prepared teeth in the cast can be removed for convenience in using the reseated in their exact original position in the base of the cast again resulting in a solid cast. This, then is truly a "master cast.

Elastic impression materials such as hydrocolloid, enable the detist to obtain a more accurate reproduction of the oral structures. The material is inserted into the mouth in a fluid state, held in an impression tray. it is then allowed to gel, or induced to gell by introducing cold water through a water jacket in the impression tray, and after complete gelation, is removed from the mouth. Its elastic nature allows the impression material to spring out of undercuts after gelation with a negligible distortion. A hard model or cast is obtained by pouring hydrocal into such an impression, allowing it to set hard and then separating it from the impression. This model or cast is then the most accurate reproduction of the mouth structures that is possible. Any prosthetic appliance restoring individual teeth or combinations of teeth if made to fit the model accurately, should then fit the mouth structures with the same accuracy.

It is therefore the primary object of this invention to provide means for simplifying the pouring of the hydrocal into the elastic impression material to obtain a hard model or cast so as to provide dowel pins centered in each prepared tooth, and parallel to each other which will allow said prepared teeth to be removed and then reseated accurately in their original positions in the master cast.

The construction of this invention features the use of a clamp which has a plurality of tapered apertures therein for reception of the dowel pins. These dowel pins are adapted to be centered in the impression of a tooth a small distance above the elastic impression material. Then the pins may be removed from the vicinity of the impression, the impression tray removed from its indexed position in the instrument, hydrocal poured into it, and both pins and impression returned to their exact original positions. The dowel p ns can then be positioned exactly as they were when previously centered due to the action of this device.

Still further objects and features of the invention reside in the provision of a pin centering and paralleling of the nature described that is strong and durable, simple in construction and manufacture, capable of being readily produced for wide distribution in the dental fields at a relatively low cost, While being highly effective in achieving highly accurate reproductions while using the new techniques necessary for proper handling of elastic impression material.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this pin centering and paralleling instrument, preferred embodiments of which have been illustrated in the accompanying drawings, by way of example only, wherein:

Figure 1 is a perspective view of the entire instrument;

Figure 2 is a vertical sectional view as taken along the plane of line 22 in Figure 1;

Figure 3 is an enlarged sectional detail view of the clamp member and the bracket pivotally attached to the clamp member;

Figure l is a perspective View illustratingone of the clamps used for centering and paralleling the dowel pins comprising important elements of this invention; 7

Figure 5 is a sectional detail view illustrating in particular the tapered apertures in the clamp member and the tapered dowel pin;

Figure 6 is a bottom plan view of one of the clamp members;

Figure 7 is a top plan view of a clamp member showing the device as provided with a set screw having a slotted head;

Figure 8 is a view of the modified form of the invention similar to that of Figure '7 but showing the set screw being provided with an Allen head; and

Figure 9 is a top plan View of a further modification of the invention employing a Phillips head screw.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral Hi generally designates a base to which a fitting I2 is secured by screws, bolts or fasteners It. The fitting I2 is provided with a tubular flange it havin a set screw it threadedly secured therein for locking engagement so as to support and hold a vertically extending stand 26. There is also secured to the base It a cylindrical member 22 having a recess 24 therein for reception of the socket elements 2t and 28 forming one portion of the ball and socket joint including the spherical member 3!! which is attached to an upwardly extending standard 32.

A threaded rod 34 is provided for tightening the socket elements 26 and 28 into clamping engagement with the spherical ball 3d. The upper end of the standard 32 terminates in an annular flange 36 to which a tray 38 preferably formed from a transparent synthetic plastic material is secured by means of bolts 40. Obviously, the tray 38 may be formed from any other material as may be desired but the use ofthe: aforesaid material has its advantages in enabling-the operator to more easily remove the plaster index holding the impression tray after using.

'Slidably embracing the stand. 2-0 is; anclamp A knurled headed thumb screw; 4.4

member 42. is used to lockingly adjust the clamp member 52 at any desired height and position on the stand 20. The clamp member 42 isprovidedwith bi-- furcations 46 and 4! between which there is received a bracket 48 which is mounted for pivotal screw. 5.3;p1usia washeris'. adaptedt -lockingh;

h ld the Supportv plate.- 56; in an adjusted position relative toy-theymounting plate St. The support. pIateEfi-isproVidedzwithianarcuate configuration asat. fifldmorder thatthedowel pin clamps as,

indicated-.at;$2.may berarranged insuch matnher as to permit the dowel pin 54 to havingthein anchors. 66, arrangedto, conform. with: the contours of a jawsand; center oftthe-prep-ared teeth of. ourimpression.

Referring nowpar.tioularly to Figures "r through 9 wherein thedoweltpin' clamps6-2;and the dowel. pin: 6% forming; the mostimportant elements. of a the invention I are: illustrated. it will be seen. that each,- of; the; doweL. pin. clamps I 5-22 are formed with a fixed lower jaw lit-.zandrmovable upper; jaw. 10.. Theupper jaw it: is,- pro- Vided-With a; recess. '22 within which inner: rib T4 is embraced.' Theinner. Ylbiformed on the, connectionIla-interconnecting'thelower jaw 10 with a fixed portion 78 used inzsupporting the upper movable jaw it. Attachedto' the-upper jaw. 10-115 a guide rod-1 all-which. extends through; an aperture in the upper portionlts. Another aperture, 82 informed inzthe-upperrportiontlii for. reception.- of, a; headed: internally threaded willhedrawn upwardly toward the .fixed. portion.

it?" or urgeddownwardly toward theloiverjaw 63..v A slot 95) for. reception. of a screw driver, isprovided in the. headed sleeve 8 1" and alter.- natively as is, shown inF'igures 8 and" tan. Allen head 9| may be provided for reception of" an Allen wrench or a Phillips headed "may alternatively be used; An outer reinforcing rib: 92""is;

provided for, the clamp trend 1 extends about thev fixed portion 78'; the. connecting portion. it. and. the lower jaw, BB2 Theportionoflthe. rib.

92.011, the lower. jaw. lifiperforms the ..additional function of providing the lower surface of the jaw 88 with portions of varying depth. This is advantageous since a plurality of tapered apertures 94 are drilled into the lower jaw 68 for reception of beveled dowel pins 64. Hence, when the dowel pins 64 are positioned in the portion of the rib 92 they will extend somewhat below the dowel pins placed in the jaw 68 proper thus permitting: greater flexibility in the: use. of this device. \Sometiines clampswith a smooth, fiat lower jaw 68 without rib 92 are used to permit all pins to be evenly positioned in lower jaw 68. These. are. desirabl in addition to clamps with rib; 92"on lower jaw 68. It is to be noted that the anchors 66 are provided with ridges and recessesih order that the plastic material being used in the cast may. become bonded thereto thus assuring against the pins being accidentally disengaged.

In operation, after the impression has been taken. it. isplaced. ina plaster of: Paris matrix on tray, 58'. 'Ehen, theclampsfiz and thepins. are. attached to the support. plate 56.- withthe anchors 56 of. the pins: 613 positioned. a small distance. above the prepared teeth. oi an elastic impression. materiall impression. The support plate. 526 is preferably formed: fromrai transparent plastic materialinorder that the impressionniay. continuously be observed thus preventing any accidental distortion. orv destructionof the. impression. Then, the clamps,.dowel.-pins.84, and the. entire. bracket. t8; may, be. rotated: upwardly. astis shown in. the.dottedlinesdnffifigure 3: and this. impressioncan beremoyedlirom its plaster oi Paris-matrixon tray 58,.filled1with .liydrocal mixture for. molding. the cast, and. returned; to originalpositibnbn tray, 58... Priorto the set.- ting oi the hydrocal mixture:the:bracket- 48;will be depressed. so. asto. immerse. the. anchors 65. in the hydrocal. mixture. This' mixture. may be heaped up. about the. anchors :ifsuch is necessary. so as toinsure. aproper. bond. In.this manner each of the desired teeth.may, be. provided, with a centrally located dowellpirr. eventhough the impressions. of the. teeth. arev not in view. after the hydrocal. mixturahas beeirpouredi.

Since. from .the foregoing, the construction and advantages of' this pin. centering and. parallels ing instrument are readily, apparent; furtherdescription is believed to be unnecessaryi.

However, since numerous modifications; willreadily occur; to those. skilled in. the. artiafter. a;- consideration' of 1 the foregoing specification and accompanying drawings,. it is. not. intended. to limit the. invention to.the. precise. embodiment-- shown and; described, but alL- suitable modificationsand. equivalents maybe readilyresorted to as desired.

What is claimed-a :=new.-:is.- asviollowsz.

1...A.-. dowel. pin centering; and paralleling. instrument for:restorative dentistry; comprisi'ng'ia; clampv for engaging, as support: said. clamp havin r an upper jaw andafilower clampingijaw adapted to I hold said plate :therebetweem. a'iplui rality-oi; spacedupwardly extending;and-tapermg:

apertures in clamp. and; a. plurality oftaperedi dowel, pins. receivedi in said: apertures; saidv dowel. pins: being. irictionally. heldby said clamp, insaicl aperturea.

2-..... dowel... pin centering..- and paralleling.

-. rality; of. spacedupwardlyextending and tapering;-

apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, the under surface of said lower jaw having more than one portion each of varying depth, said apertures being arranged in parallel rows along the said portions.

3. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping jaw adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said apertures being arranged in parallel rows.

4. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping law adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member.

5. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping jaw adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member, the under surface of said lower jaw having more than one portion each of varying depth, said apertures being arranged in parallel rows along the said portions.

6. A dowel pin centering and paralleling in strument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping jaw adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member, said apertures being arranged in parallel rows.

7. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping jaw adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member, said clamp member having a bifurcated outer free end portion, said bracket being pivotally secured within said bifurcated free end portion, said bracket having a projecting stop member extending inwardly of said bifurcated portion and selectively abutting against said clamp member to provide a limit stop to the rotation of said bracket relative to said clamp member.

8. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw ani a lower clamping jaw adapted to hold said plate therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member, said clamp member having a bifurcated outer free end portion, said bracket being pivotally secured within said bifurcated free end portion, said bracket having a projecting stop member extending inwardly of said bifurcated portion and selectively abutting against said clamp member to provide a limit stop to the rotation of said bracket relative to said clamp member, the under surface of said lower jaw having more than one portion each of varying depth, said apertures being arranged in parallel rows along the said portions.

9. A dowel pin centering and paralleling instrument for restorative dentistry comprising a clamp for engaging a support plate, said clamp having an upper jaw and a lower clamping jaw adapted to hold said plat therebetween, a plurality of spaced upwardly extending and tapering apertures in said clamp, and a plurality of tapered dowel pins received in said apertures, said dowel pins being frictionally held by said clamp in said apertures, said clamp being supported by said plate over a tray, said plate being adjustably secured to a bracket, a base, a stand on said base, a clamp member vertically adjustable on said stand, said bracket being pivotally attached to said clamp member, said clamp member having a bifurcated outer free end portion, said bracket being pivotally secured within said bifurcated free end portion, said bracket having a projecting stop member extending inwardly of said bifurcated portion and selectively abutting against said clamp member to provide a limit stop to the rotation of said bracket relative to said clamp member, said apertures being arranged in parallel rows.

ARVIN W. MANN.

References Cited in the file of this patent UNITED STATES PATENTS Number

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