US2456447A - Dental surveying instrument - Google Patents

Description

-1 v .Jl RINGLE HAL 2,456 4 7 DENTAL SURVEYING INSTRUMENT Filed NOV. 2, 1945 2 Sheets-Sheet l @f Z o 50 35 {I Q q 5 I INVENTORS, M .Z...) a,

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Patented Dec. 14, 1948 DENTAL SURVEYING INSTRUMENT Charles J. Ringle and Roy w. Smith, Buifalo, N. Y., assignors to Williams Gold Refining Company, Inc., a corporation of New York Application November 2, 1945, Serial No. 626,327

This invention relates to certain new and useful improvements in dental surveying instruments of the type shown in United States Patent No. 2,376,384, dated May 22, 1945.

One of its objects is to provide a dental instrument of this character having a universallytiltable, model-supporting table having means for adjusting and indicating its degree of tilt in any direction, and to so mount the table and its actuating means as to effectually compensate for the gearing as Well as for wear of the parts during use.

Other features of the invention reside in the construction and arrangement of parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a top plan view of the surveying instrument embodying our invention. Figures 2 and 3 are enlarged cross-sections thereof taken substantially in the planes of the correspondingly numbered lines in Figure 1. Figure 4 is a horizontal section taken substantially in the plane of line l4, Figure 2.

Similar characters of reference indicate corresponding parts throughout the several views.

The numeral lfl indicating the base or platform on which the various working parts of the surveyor are mounted, is smoothly machined in a horizontal plane on its top side to provide a support for the surveying mechanism, indicated generally by the numeral ll. Rising from this base at one side thereof is a post or standard !2 on which is mounted a vertically-jointed, tool-carrying arm [3 onwhich the various tools used in surveying dentures are adapted to be detachably mounted.

Mounted on the top side of the base ID to be rotated thereon at will, or to be clamped in a fixed position thereto, is the casing [4 of the surveying mechanism which carries a universallymovable working table l5 for supporting the model it to be surveyed. Clamping screws I! fitted into the base Ill and engaging the flanged bottom of the casing serve to detachably secure the latter to the base. The casing is cylindrical in shape and the working table l5 surmount-s the same for tilting movement in any direction to the horizontal. By preference, a removable working plate I8 is applied to the top side of the table and the model I6 is anchored thereto. This working plate is centered and held against lateral displacement on the table by means of pins l9 and a cam lever 20 rising 2 Claims. (Cl. 3232) from the latter and engaging companion openings in the plate.

The means for eifecting the universal adjustment of the tiltable table l5 for surveying purposes is preferably constructed as follows:

The numeral 2| indicates a shiftable yoke which is fastened at its lower end on a horizontal pivot shaft 22 extending diametrically across and journaled in the lower portion of the casing l4, while its upper end terminates in bifurcated arms 23 in which is journaled a horizontal shaft 24 disposed at right angles to the pivot-shaft 22. Depending from the working table are spaced arms 25 which are connected to the opposite ends of the shaft 24, so that when the latter is turned in one direction or the other, the working table is correspondingly tilted in anterior and posterior directions. This yoke is provided between its pivoted lower end and its bifurcated upper portion with a bear-ing or bracket portion 26 disposed parallel to the pivot-shaft 22 and in which is journaled an actuating shaft having a worm 28 thereon meshing with a worm wheel sector 29 pinned on the shaft 24. At its outer end the shaft 21 is provided with an actuating knob 30 for turning it and the worm gears to tilt the working table in anterior and posterior directions. The tilting movement of the working table in the opposite direction, that is its socalled minus and plus movement, is controlled by an actuating shaft 3| disposed at right angles to the companion actuating shaft 2? and extending through a bearing bracket 32 in the casing and having a worm 33 mounted thereon engaging a worm wheel sector 34 fixed on the yokepivoting shaft 22. At its outer end the shaft 3! is provided with an actuating knob 35 for turning it and the corresponding worm gears to tilt the working table in a lateral or minus-plus direction. Suitable indicators are provided for registering the degree of anterior and posterior tilt as well as the minus-plus tilt of the working table. For registering the anterior and posterior tilt a graduated scale 36 is applied to one side of the working table and cooperating therewith is a stationary pointer 31 fixed to the side of the adjoining yoke-arm 23, so that as the table is manipulated in its anterior and posterior movements by the actuating knob 30, the scale 36 is tilted with it relative to the pointer. For registering the minus-plus tilt the casing it is provided with a graduated scale 38 disposed above the axis of the actuating shaft 2'! and cooperating therewith is a stationary pointer 39 applied to the adjoining end of the bearing portion 26 wear of the rotating parts, the knob-actuated shafts 21 and 3! are preferably mounted as follows, and in this connection each mounting is the same and a descriptionrof one will-sufficefor both:

Each of the actuated shafts 27, 31* extends freely or in spaced relation through its. companion.

bearing bracket 25, 32 and appliedto the front end of each shaft between the actuating knob' thereof and the opposing end of the bracket is a bearing collar 40 having an inwardly-extending sleeve 4'! which fits freely within the bore 42 ofsuch bracket. This collar is free to permit a limited angular displacement of the shaft in the bracket bearing. and aradially-disposed spring 43 housed in-a hollow fitting 44 mounted on the bearing bracket and bearing; atits inner end against the collar-sleeve 4|, serves to normally urgethe: Worm 28 or '33 into" proper mesh with thercompanionvwormiwheel- sector 25 or 34; Applied to each. of theshafts 2:1, 31- between said collar. andthe worm gear 28 or 3'3 is a swivel bearing 65 which constitutes a fulcrum' for the angular displacement of; each shaft and bears on the inner. end of the bracket-borefl, the latter converging at such inner end. to form .a' stop 46 against which theswivelbearing is adapted toabut. A coil spring 41 is applied to each shaft and bears at one end against the collar-sleeve M and at its other end against the swivel bearing 45' thereby stabilizing the: position of these parts by constantly urging the swiveLbearing'im Wardly againstthe stop: 46 and each shaft together with its worm in the opposite direction or outwardly torbringjsuch worm into proper and positive mesh with the companion worm wheel 2901*3;

By mounting theiknob-actuated shaftsin this manner, they are permitted: a yieldingly re.-

strained angular displacement and a relative axial displacement: so as tor at all times assure proper meshing" of. the: gears: and" accurate adjustment of the table to thextilt'ed' positions desired withoutobjectionable lost motionr Furthermore, as the" parts wear from continued use, they are. automatically adjustable; through the medium of the springs fi3 andand the swivel bearings 48-, to compensate for such wear.

We claim as our invention:

1. A dental instrument of the character described, comprising a supporting member, a table surmounting the same for tilting movement, a bearing bracket having a longitudinal bore therein converging inwardly at one end thereof, a bearing sleeveextending loosely into one end of said b'oreg anraxially-displaceable swivel bearing in the opposite converging end thereof, a shaft extending through and journaled in said bearing sleeve and said swivel bearing, gearing between the shaft-and: the table for tilting the latter in response to the actuation of said shaft, the shaftgear' being, mounted on the extended end of the shaft beyond the. swivel bearing and abutting at its other end against the opposing end of the bearingbracke't; and a spring applied to said a bearing sleeve extending loosely into one end of'said bore, anaxially displaceable swivel bearing; in the opposite converging end thereof, a shaft extending through and journaledin said bearing sleeve and said swivel bearing, said shaft having anactuating, knob at its outer end and said sleeve having a collar at itsouter end interposed between said shaft-knob'and the opposing end of said bracket, gearing between the shaft and the table for tilting the latter in response to the actuation of said shaft, the shaft-gear being mounted on the extended end of the shaft beyond the swivel bea-ring and abutting at its other endagainst the opposing" end of the bearing bracket, a spring applied to-s aid shaft and interposed between s'a-idRsle'eve and said swivel bearing, and yield'able means acting at right angles to-said shaft for constantly urging it in one direction about the swivel'bearing.

CHARLES J. RINGLE. ROY SMITH.

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

s'ra'rns PATENTS Germ-any Mar. 17, 1922

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