US 2018679 A
Description (OCR text may contain errors)
Oct. 29, 1935. J. l. LAWSON DENTAL ARTICULATQR Filed Nov. 20, 1954 BY N ATTORNEYS Patented Oct. 29, 1935 UNITED STATES PATENT OFFIQE 1 Claim.
of which proper occlusion of dentures will be obtained. Other objects will appear in the course of the following description of a device embodying the invention which resides in certain novel features particularly set forth in the appended claim.
In the drawing:
Figure 1 is a perspective view of the articulator.
Figure 2 is a vertical section.
Figure 3 is a detail section on the line 33 of Figure 2.
Figure 4 is a perspective view showing a modification.
In carrying out the present invention, there is provided a lower plate I which is of skeleton construction so that when a plaster cast is applied thereto the plate will be partly embedded and the cast firmly held. Upon the edge of the plate is an extension 2 from which rise spaced parallel lugs 3 connected at their outer vertical edges by a web 4 which, as shown clearly in Figure 2, terminates short of the upper ends of the lugs, the lugs and the web being integral with the plate. Pivoted at its lower end to and between the lugs 3 is a stem or standard 5 which is preferably rectangular in cross section and may be of any desired length. The lower extremity of the standard is below the pivot and the pivot is so located that when the standard is raised, as shown in full lines in Figure 2, its lower end will bear against the web 4 and the standard cannot swing forward and down under the weight of a denture or cast. When the standard is swung back and down, as shown by dotted lines in Figure 2, it will rest upon and be supported by the web, and the parts should be so proportioned that the standard will fit closely between the lugs and be thereby prevented from swaying laterally but will turn easily when it is to be raised or lowered.
An upper plate 6 is provided having substantially the same contour as the lower plate and also of skeleton construction. The extension 1 of the upper plate, however, is wider than the extension 2 of the lower plate and has guide ribs 8 along its edges on its upper side between which fits an arm 9. Said arm 9 is formed with a longitudinal slot through which a thumb screw or bolt II is inserted to engage a threaded opening in the extension I and thereby secure the upper plate in a set position, a washer or a shoulder 12 being provided under the head of the screw to span the slot and clamp the arm and plate together as the screw is turned home. The arm 5 9 extends from a collar l3 which fits snugly but slidably around the standard and is held in a set position on the standard by a thumb screw l4 mounted in the collar to be turned home against the standard. The non-circular cross section of 10 the standard and of the bore of the collar aid the thumb screw in preventing lateral swaying of the arm after it has been adjusted vertically on the standard. A set screw 24 mounted in the side of the collar I3 prevents lost-motion in the 16 event of Wear.
In the variation shown in Figure 4, the lower plate has a fiat-sided post I5 thereon and the standard l6 has its lower end formed into a fork II which fits over the upper end of the post and 20 is pivoted thereto, the ends of the fork having arcuate edge portions I8 concentric with the pivot and stop shoulders I9 to abut stop lugs or studs 20 on the post and thereby prevent the standard rocking downwardly and forwardly. 25
The use of the device will be readily understood. The casts, indicated at 2| and 22, are mounted on the upper and lower plates and the teeth 23 are fitted on the casts, the arm 9 being adjusted vertically on the standard according to 80 the length of the teeth. By adjusting the upper plate upon the arm 9 the upper denture can be properly centered over the lower denture and the ribs 8 effectually prevent lateral slipping of the plate. By rocking the standard on its pivot 35 until it rests on the web 4 or the studs 20, as the case may be, the dentures will be firmly supported while adjustments of the teeth are made and the occlusion and bite of the teeth may be closely observed by slowly rocking the standard to open and close the dentures.
Having described my invention, what I claim is:
A dental articulator comprising a lower plate,
a pair of upstanding lugs on said plate, a web connecting the outer edges of the lugs and terminating short of the upper ends of the lugs, a standard pivoted adjacent its lower end to and between the lugs and arranged to bear against the front face of the web or rest across the upper end of the web, and an upper plate carried by the standard.
JAMES IRA LAWSON.