US2318403A - Device for the parallel guidance of dental tools - Google Patents

Description

y I K. A. s. KARLSTRGM 2,318,403

DEVICE FOR THE :PARALLEL GUIDANCE OF DENTAL TOOLS Filed Jan. 2, 1942 z sneets-sheet 1 @"M gggs.

1943-7 A. s. KARLSTROM 2,318,403

DEVICE FOR THE PARALLEL GUIDANCE OF DENTAL TOOLS Filed Jan. 2, 1942 2 Sheets-Shea]; 2

95 mum mum 6 wwi gg ys Patented May 4, 1943 DEVICE FOR THE PARALLEL GUIDANCE OF DENTAL TOOLS Karl Axel Sam Karlstriim, Gavle, Sweden Application January 2, 1942, Serial No. 425,470 In Sweden February '7, 1941 4 Claims. (01. 32-67) The present invention relates to those devices for the parallel guidance of dental tools Which are intended to be placed in the mouth and in which a guiding sleeve for the tool is carried by a support adapted to be fixed relatively to the teeth, and is swingably mounted around a pin running parallel to the axis of the guiding sleeve. Such devices have hitherto only been used for drilling mutually parallel pin holes which extend substantially in the longitudinal direction of the tooth. The present invention contemplates drilling of holes which extend substantially at right angles to the longitudinal direction of the tooth. The invention is characterized substantially in that the pin carrying the guiding sleeve extends substantially at right angles to the longitudinal direction of the teeth, and is adjustable in different radial planes relatively to an axis substantially parallel to the longitudinal direction of the teeth, and preferably also adjustable into different angular positions in each radial plane. This makes possible an exact and convenient adjustment of the guiding sleeve and thus the tool to any desired position relatively to the tooth.

The device may obviously also be used for guiding grinding tools in those cases where grinding surfaces running substantially in the longitudinal direction of the tooth are to be prepared.

The invention will be more fully described with reference to the accompanying drawings, in which Figure 1 is a side view and Figure 2 a plan view of the device. Figure 3 is a cross section and Figure 4 a plan view of the device on an enlarged scale. Figure 5 shows another embodiment of the device as seen from the side and partly in section. Figure 6 shows the device as seen from above. Figure '7 shows a part of the ball-and-socket joint as seen from above.

The device is intended to be fixed relatively to the teeth by means of a plastic mass 2 which is hard at ordinary temperatures and in which the support 4 is embedded and which is cast into the fore jaw portion, as shown in Figure l. The support consists of a V-shaped base plate 4 having two inwardly directed legs 5, 6, the edges of which are waved, as shown in Figure 3 or otherwise shaped so as to hold the support firmly in the casting mass 4. The support should be so arranged relatively to the teeth that an upright 3 carrying the guiding sleeve and its pin will be situated approximately in the centre of the are formed by the fore portion of the row of teeth. The upright 3 is connected to the plate 4 by means of a ball-and-socket joint in such manner that it can be set in different inclined positions relatively to the support. The ball-andsocket joint consists of a semi-spherical member 8 riveted to the plate 4, a calotteshaped member 9 connected to the upright 3 as well as a bushing I0 embracing said two parts and having an inner bearing surface concentric with the semi-spherical member 8. The bushing Ill is secured to the plate 4 by means of screws I I, by the tightening of which the friction resistance in the ball-and-socket joint may be given a suitable value, so as to allow the upright 3 to be set in different inclined positions against the action of the friction resistance and then remain in the adjusted position, without the screws II having to be further tightened.

The upright 3 is provided with a radially extending arm l2 which forms the pivot pin carrying the guiding sleeve I3. The guiding sleeve is swingably mounted on the pin through the medium of a link arm I4, I5 and a nut I6 which is threaded on to the pin and by means of which the link arm may be set at different distances from the teeth. By means of the ball-and-socket joint the guiding sleeve can be set in the correct position relatively to the tooth in which the pin holes are to be drilled, so that the holes come into correct positions relatively to the longitudinal and transverse directions of the tooth. To facilitate the resetting of the guiding sleeve in a previously adjusted position, the ball-andsocket joint is provided with graduations, as shown in Figure 4. The graduations are arranged on the adjacent portions of members 9 and III, the latter being provided with a graduation I! arranged round the edge of the central opening and consisting of radially disposed scale lines, while the visible part of member 9 is provided with scale lines in the form of a number of concentric circles I8 and preferably also one or more radial scale lines I9. When the pivot pin I2 is to be reset in a position previously occupied, the upright 3 is turned by means of the arm I2, until the scale line I9 comes opposite the desired scale line of the scale II, whereupon the upright is tilted forwards and backwards, until one of the circles I8 touches the inner edge of the scale II at one of the scale lines I9 lying in the radial plane of the pin I2. By the firstnamed setting the guiding sleeve or the drill is adjusted to a direction substantially perpendicular to the transverse direction of the tooth, while the lattter setting designs to adjust the direction of the drill to the inclination of the tooth, so that the bore holes will be substantially perpendicular to the longitudinal direction of the tooth. It is,

however, obvious that by this arrangement the drill may be given other directions relatively to the tooth. After the pivot pin l2 has been adjusted in the desired manner to a certain tooth, several mutually parallel holes may be drilled in the tooth, in that the guiding sleeve l3, thanks to the link arm 14, it may be parallelly displaced laterally as well as upwards and downwards, without the position of the pin l2 having to be altered.

The setting of the upright 3 in different positions of inclination may also be effected in another manner than by means of a ball-andsocket joint. Thus, the upright may, by both its ends, be fixed in the support and adapted tobe set in different angular positions relatively to said support in the manner shown in the copending Patent application No. 348,914 of July 31, 1940. The device described may also be modified in such manner that the upright 3 is rigidly fixed in the support, while the pin I2 is pivotally connected to the upright in such a way that it may be swung around the upright as well as given difierent positions of inclination by being turned around an axis perpendicular to the upright;

In the embodiment shown in Figures 5 to 7, the pivot pin 2! forms, as in Figures 1 to 4, an arm extending radially from the upright 22 and rigidly connected to theupper endof the upright. The lower end 23 of the upright is semispherical in shape and fitted into a bushing 24 which is semi-spherical onthe inside and removably connected to the support 25, which, as in Figures 1 to 4, consists of a central plate 25 and two legs 2B, 2? extending from said plate. The bushing 24 is conical on the outside andkept fixed to the plate 25 by means of three lugs 23 extending from said plate and embracing the lower edge of the bushing. In the assembly of the ball-and-socket joint the bushing 24 is first placed in such a position that a notch 29 made in the edge comes opposite one of the lugs 28, whereupon the bushing is locked by being turned so that the notch 29 will be positioned between two lugs 28.

The upright 22 is in this embodiment tubular and threaded on to a central pin 30 threaded into the lower semispherical part 23. The pin 23, which is provided at its upper end with a head 3!, bears by its lower end against a pivot 32 riveted to the plate 25 and having a semispherical upper surface concentric with the bearing surface of the ball-and-socket joint. After the upright 22 has been set in the desired position of inclination, the central pin 39 is turned by means of the head 31, whereas the spherical surface of part 23 is kept in frictional engage ment with the inner surface of the bushing 24. Part 23 will then be screwed on to the central pin 30 and pressed against the inner side of the 1 bushing 24 so as to lock the upright in the adjusted position. To change the position of adjustment, the upright is loosened by turning the pin 3% in the opposite direction. The guiding sleeve 36 is, as in Figures 1 to 4, swingably mounted by means of a double link 35, 36 on the pivot pin 2i through the medium of a nut 31 which is threaded on to the pin and by means of which the link arm and the guiding sleeve can be set at different distances from the teeth.

The pivot pin 2! and the centre pin 30 have preferably the same diameter and the same thread, so that they may alternatively be used as an axis of oscillation for the guiding sleeve. If e. g. it is desired to pass from drilling transverse holes to drilling longitudinal holes, this may be effected by removing the pivot pin 2| and the upright 22 from the ball-and-socket joint and inserting instead a part corresponding to the semi-spherical part 23, into which the centre pin 35) is threaded and by means of which the pin 30 may be locked in different angular positions in the manner just described with reference to the upright 22. The centre pin'30, extending from the ball-and-socket joint, being now free, it may be used as an axis of oscillation for the guiding sleeve 34 and the link arms 35,36, after the nut 31 has been threaded on to said pin.

The bushing may, as shown in Figure 7, be provided with a scale adapted to be used together with scale lines or the like on part 23v for setting the upright 22 or the pin 2| in fixed angular positions.

I claim:

1. Device for the parallel guidance of denta tools, in which a guiding sleeve for the tool is carried by a support adapted to be fixed relatively to t .e teeth, and is swingably mounted around a pin running parallel to the axis of the guiding sleeve, characterized in that the pin extends substantially at right angles to the longitudinal direction of the teeth, and is adjustable in different radial planes relatively to an axis substantially parallel to the longitudinal direction of the teeth, and preferably also adjustable into diiierent angular positions in each radial plane.

2. Device as claimed in claim 1, characterized in that the pin is carried by an upright which is substantially parallel to the longitudinal direction of the teeth and adjustable into different angular positions relatively to the support.

3. Device as claimed in claim 1 in which the pin is carried by an upright extending substantially at right angle to the pin and connected to the support by means of a ball-and-socket joint.

4. Device as claimed in claim 1, in which the pin is carried by an upright extending substantially at right angle to the pin, said upright being tubular and threaded on to a center pin adapted to be fixed in different angular positions relatively to the support.

KARL AXEL SAM KARLSTROM.

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