US2603869A

US2603869A - Articulator for artificial dentures

Info

Publication number: US2603869A
Application number: US650783A
Authority: US
Inventors: Bjorklund Gustaf Erik
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-03-05
Filing date: 1946-02-28
Publication date: 1952-07-22
Anticipated expiration: 1969-07-22

Description

July 1952 l G. E. BJGRKLUND ,6

. ARTICULATOR FOR ARTIFICIAL DENTURES Filed Feb. 28, 1946 3 Sheets-Sheet l INVENTOR AQA'ATTORNEY July 22; 1952 V G. E. BJORKLUND 2,603,869

ARTICULATOR FOR ARTIFICIAL DENTURES Filed Feb. 28, 1946 5 Sheets-Sheet 2 INVENTOR 4/ M W W/M MTTORNEY Patented July 22, 1952 mm STATES PATENT OFFICE 1 2,603,869 I Y .ARTICULATOR. FOR ARTIFICIAL DENTURES Gustaf Erik Bjorklund, Stockholm, Sweden Application mamas, 1946,.SerialNo. 650,783

. .In Sweden March 5, 1945'v 7 Claims. (01; 32- 32) .In the manufacturing called, articulators are used in order to make possible an application of the teeth on the den? tures .whereby the chewing motion natural to the patient. is attained. These articulators are principally. composed o f-a lower part and an upper. part which can be moved in relation to each other. in about the same way as the lower jaw movesgin relation to the upperjaw. When the articulator is used the position of thepatients chewing surfaces are localized in relation to the centre. of motion of the jaw mechanism by means of certain measuring instruments. Thereafter h Se-measurements as a base models of-the jaws "arex-formed and put into the articulator, the .upperjawmodelbeing attached to the upper part and the lower jaw model to the lower part. The articulator is provided with such adjustin arrangements. as to enable the surgeon to adjust the same in'Such a way that the models can carryout the same movements as, the patients jaws.

. The manufacturing of the dentures in conformity to-the models is thereafter not performed by the dentist but by a dental technician. In order to. carry out his work in theright way the latter neets-access tonot only themodels but also the articulator. with the adjustments made .by the dentist; As the technicianmay have his workshiplocated at aplace far away from the locality of artificial dentures so of..the ,.dentists office it is not practical to send the whole articulator. Even if this could be done withoutinconvenience there "is. always the risk ofathe articulatorv'being deformed or otherwise damaged during transportation so; that the same adjustment doesnot correspond to the actual jaw motion. Because of this the technician should be provided-with .an articulator which coincides with the dentist's articulator so, that the models maybe moved from one articulator to the other without any divergences arising. However it'has proved difficult tomanufacture articulators with such Close tolerances. Even if the articulators are exactly alike when new they may be altered little by little on account of careless usage or wear... I I

-;:The present invention has for its purpose to remedy these drawbacksand consists in the articulator being provided with arrangements which make it possible forthe dentist as well as the technician to control and adjust their articulators to such, a coincidence .thatthemodels can be moved from one, articulator to another without ,ilf ltroduciiigerrors and inaccuracies. According to thefjinvention avfirm but releasable coupling is inserted between theupper part' of the articii-- lator and the lower part in such a way that the position of the upper part can be adjusted in relation to the lower part. In orderto ensure the right adjustment of the articulator the upper part and the lower part are locked in their cor rect relative positions by means of a sage fixture or the like.

In the following the invention will be further described with reference to the annexed drawings in which Fig. 1 shows an example of an articulator constructed according to the invention as seen from one side. Fig. 2 shows the same articulator as seen from the front. Fig. 3 shows a section of the articulator on the line 3+3 of Fig; 2 .and Fig. 4 shows a section ofha. slightly modified form of the articulator coupling.

In the figures .l indicates the upper'partjof the articulator and 2 the lower part. In the latter two holders 3' and 4 are fastened, which at the top carry the bearing supports for the upper part. In Fig. 2 theholder 4 is shown partially in section by means of which the construction will be made clear. The

holders

3 and 4 consist of a fixed lower part in'whi'ch an'upper' part 5 is pivotally arranged by means of a journal 6. The pivotal part can be adjusted and locked inany given position relative to the lower part through a locking screw 1, this position being indicated on a scale 8. In the upper holder part 5'two journal rings 9 are fixed which support a condyle slide l0 which can be turned in the journal rings and locked in a given position relative to these through a lockingscrew II, which also acts as a handle, when the condyle slide isto'be turned. The angular position of the condyle-slide is in-.- dicated on a scale l2. In the condyle slide is a rectangular notch the upper and lower surfaces of which are provided with grooves thus forming a condyle track in which a, hearing ball I 3 travels.

The bearing balls 1 l3 travelling in the condyle tracks of the

holders

3 and 4 are provided with transverse bores and are able to slide and rotate freely on journal pins l4. These pins are coaxially fixed on an intermediate member I5, which alsosupports the upper part I of the articulator and is connected with the same through a firm but releasable coupling the construction of which will be more evident from an inspec tionofFig.3.-

The upper part I is formed as an elongated beamthe'lcross. sectional area of which is somewhat increased at the rear end where the beam has a plane end surface I6 perpendicular to the longitudinal axisof thebeam. 'On this surface and a washer 20 lying between the head of the screw and the larger end surface of the inner conical ring IS, the ring [8 can be pressed into the outer ring I! toward the surface [6. Thereby the ring ll will be expanded andfirmly-locke'd in the recess of the intermediate member l5 and a at the same time be pressed against the planeend surface [6 of the upper part and locked to the same. locked to the intermediate member I5 by tightening the screw. 7 1

The internal diameter of the inner conical ring 18 is much larger than the diameter of thescrew l9 and therefore a space is formed between these parts; which after the screw has been loosened allows a certain displacement of the upper part I in any desired direction in the plane of the path, the-upper part'l' being also displaced a distance in the plane of the surface lS' corresponding to' the upward or downward movement of the intermediate member I5. It will also'be apparent that with the screw [9 loosened the upper part I may be turned about its own longi-' tudinal axis which is perpendicular to the plane of the surface It and that a certain angular displacement of the surface It relative to the centre line of the journal pins It is possible because of the spherical surface of the recess in the inter mediate member From what precedes it will be seen that the coupling formed by the conical rings [1 'and I8 makes possible free movement within certain limitsof the upper part I in relation to the intermediate member 15 and consequently. in relation-to the lower part 2.

'Infthe fore end of the upper part I a pin2l is journalled as a slide in a bushing 22. The pin may be f xed in a given position bymeans of-alock'ing screw 23 and a scale 24 onthej pin indicates: its position; The upper pa rtfbffthe piiris-beni; to arcuateform, the centre of the are lying onthe centre line of the journal pins H! by means of whichthe position of the pin can be altered without altering its location relative to the lower part2; The lower tapered end of the pin 21 rests upon a plane surface 25 formed by a flat piece which is arranged on a semicircular p'late'26. Thearcuate periphery of the plate 26 is slidably journalled in a holder 2'! in In this way the upper part I may be 4 placed. The holder 21 is firmly disposed in the lower part 2 and is provided with a locking screw 28 for the plate 26 which is equipped with a scale 29 on which the angular position of the plane surface is indicated.

On the upper plane surface of the lower part 2 a lower model fastening means in the form of a plate 30 may be attached with a screw 3|. The plate 3tis provided with locating pins 32 which engage in corresponding bores in the lower part 2. In the same way an upper model fastening means 33 with locating pins 34 may be ar ranged 'on the lower plane side of the upper part I and be fixed with an attaching screw 35.

If desired the construction of the articulator .described above may becaltered in difierent ways within the scope of the invention. Fig. 4 shows as an example a modified form of coupling. In this case the outer conical split ring I! is provided with a cylindrical outer surface and is surrounded by a further split ring'36 the inner surface ofavhich is cylindrical and outer surface spherical. The'ring 3B-isdisposed with its spherical surface in the spherical recess-of the intermediate member I5 the centre of 'therecess in this case being located'on thecentre line of the journal pins H5. The coupling of the latter modified form has substantially the same function as the coupling shown in'Fig. 3. The dis placement of the upper part perpendicularly to the plane 16 may however in this case be madeby displacing the conical ring l1 axially in .the ring'36.' r J The location and construction of the coupling may of course be varied in numerous other ways; It may-thus be placed in the lower part or-in the holders for the upper part oratthe attaching screws for the mod'el fastenings. The coupling may also'be provided with separate adjusting and locking arrangements for displacement in different planes or directions of the upper and/or lower part. i

Essentially the invention'makes it possible to always obtain the same position of the upper part i withrelation to the lower part 2 when all the adjusting arrangements of-the articulator are properly set. Inorderto-obtainan exactmand unvarying adjustment of=the articulator in this respect a gage fixture-fillshown in Fig. 3: in

such way that the angle between the centre line Y of the pin 2| and the plane surface 25 may be altered by displacing the plate in the .holder. The centre axis of the arcuate bearing surface lies in the plane 25 and is perpendicular to the plane of symmetry of the articulator so that the plate moves in this plane when being dis-' the relative; positions ,of j hese' *partsf shoul v or screw dottedlines) maybe employedw The fixture-1'1 is-=providedwith plane end surfaces forkconta'cl: with the upper: and lower partsg guidingpins corresponding to the pins 32 and34 in themodel fastenings, and threads for. the attaching screws 3-] and The fixtureisxso dimensioned that the mutual distance of the end surfaces and: the position of the guiding pins 1 exactly coincide with the desired distance "between the upper and lowerparts and the positions of :the bores respec tively when the articulator is normally set i.-e. when the scales 8, I2, 24 and .29 are set :atize'ro and both theba1ls13rest upon the bottomsof the rectangular notches of the condylezsl'idesiifl as 'sh'own'in Fig;- 1'.fl 1 5' When the articulatorisito be adjusted it i's first brought to the normal setting mentioned above and the model fastenings 30 and 331 are removed and the locking screw leao'f thebou pling is loosened; The gage Zfixture 3! "is there afterjattached to the upper andlower pa means "of the screws 3 'and fifths upper I .d he. 0 35 bein t ee a sume pro e on. in ,rela i' nit he wer par ii any reason'hav'e becomeiiico'rrec't. The

I9 is thereafter tightened and the articulator is ready for use after the gage fixture 31 has been removed.

What I claim is:

1. In an articulator for artificial dentures, an upper part adapted to support an upper jaw model, a lower part adapted to support a lower jaw model, primary coupling means permitting controlled relative movements of said parts, adjusting means including scales arranged to set said coupling means for predetermined movements of the upper part in relation to the lower part during the use of the articulator, and a second adjusting means comprising a releasable universal coupling between the upper part and the lower part independent of said primary coupling means, said universal coupling when released permitting limited vertical, horizontal and axial movement of the upper part relative to the lower part and independent of the first adjusting means while maintaining the axes of said upper and lower parts substantially parallel, whereby to enable said parts to be brought into exact predetermined fixed position relative to each other for correcting any existing inaccuracies in the zeroing of said scales.

2. An articulator according to claim 1, characterized in that the upper part is releasably connected with a cross member journalled in holders carried by said lower part.

3. An articulator according to claim 2, characterized in that the releasable coupling is adapted to permit universal displacement of the upper part with respect to a plane parallel to the center line of the cross member and to permit the upper partto be turned about an axis perpendicular to said plane.

4. An articulator according to claim 3 in which the releasable coupling means is adapted to permit limited angular displacement of the adjusting plane relative to the center line of the cross member.

5. An articulator according to claim 2, characterized in that the secondary coupling means comprises an internally conical split ring arranged in a recess in the cross member, one end of said ring resting against a plane surface formed in the upper part, and an outwardly shape, the center of the spherical surface of the recess being located eccentrically in relation to the center line of the cross member whereby the displacement of the upper part perpendicular to the adjusting plane can be effected by turning the cross member about its journal and at the same time displacing the split ring on the plane surface of the upper part.

'7. An articulator according to claim 6, characterized in that the split ring is provided with an outer cylindrical surface and that a further split ring, the inner surface of which is cylindrical and the outer surface of which is spherical, is arranged about the first mentioned ring and fits in the recess of the cross member which is provided with a corresponding spherical'surface.

. GUSTAE' ERIK BJCSRKLUND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS C'ayo May 9, 1944