US2861484A - Devices for effecting adjustments in two dimensions - Google Patents

Description

J. A. RANGE Nov. 25, 1958 DEVICES FOR EFFECTING ADJUSTMENTS IN TWO DIMENSIONS 2 Sheets-Sheet 1 Filed July 22, 1955 FIG.2

J. A. RANGE DEVICES FOR EFFECTING ADJUSTMENTS IN TWO DIMENSIONS Filed July 22, 1955 2 Sheets-Sheet 2 +11 FIGS FIG.6

IIIIIIIIIIII1 FIGJO DEVICES FOR EFFECTING ADJUSTMENTS IN TWO DIMENSIONS Jack Allen Rance, Northolt, England, assignor to Aviamac Limited, London, England, a British company Application July 22, 1955, Serial No. 523,918 Claims priority, application Great Britain July 22, 1154 4 Claims. (CI. 7762) This invention relates to devices whereby a given part may be accurately adjusted in two dimensions. The object of the invention is the provision of improvements in such devices. The invention consists broadly of a device for accurately adjusting a given part in two dimensions relative to a base element, wherein said given part is carried by a first element which rotates about a first axis relative to a second element, which in turn rotates about a second axisrelative to said base element, said given part being eccentric with respect to said first axis, and said first axis being eccentric with respect to said second axis. 7

In order that the invention may be the more clearly understood, a jig in accordance therewith, by which a guide bush for a drill, reamer or the like may be adjusted accurately over a given point on the surface of a Workpiece, will now be described reference being made to the accompanying drawings wherein:

Figure 1 is a plan of said jig;

Figure 2 is a cross section of the of Figure 1;

Figure 3 is a plan of a part of said jig, hereinafter called the circular outer element;

Figure 4 is a part sectional elevation of the same on line IV-IV of Figure 3 Figure 5 is a plan of a part of said jig, hereinafter called the circular inner element;

Figure 6 is a part sectional elevation of the same on line VI-VI of Figure 5;

Figure 7 is a plan of an actuating plate by means of which the circular inner element is rotated;

Figure 8 is a part sectional elevation of the same, on line VHI-Vll of Figure 7;

Figure 9 is a plan of an actuating plate by means of which the circular outer element is rotated;

Figure 10 is a part sectional elevation of the same, on line XX of Figure 9; and

Figure 11 is a part sectional elevation of a sighting device.

Referring to the drawings, the guide bush 1 is adapted same on line III I to fit in a hole 2 (Figures 5 and 6) formed eccentrically in 'a circular inner element 3, which circular inner element is rotatable in a hole 4 (Figures 3 and 4) formed States atent 2,861,484 Patented Nov. 25, 1958 lar sighting device (Figure 11) has its end portion 8 fitted into the hole 2 in the circular inner. element 3 in place of the guide bush 1. The device contains an eye piece in which 'a magnifier 9 is set so that the surface of the work-piece can be viewed, and has at the other end a transparent window 10 marked with cross hair lines whose crossing point is seen to coincide with said given point on the work-piece when'the axis of the hole 2 in the circular inner element 3 coincides with said given point. Said sighting device is fitted with a small electric light 11 whereby the viewed portion of the sur face of the work-piece is brightly illuminated.

In order that the circular inner and outer elements 3 and 5 may be locked against rotation when the adjustment has been completed, the outer periphery of the circular inner element 3 is made conical instead of cylindrical, the smaller diameter being at the end remote from the work-piece 7. Also said circular inner element has an external shoulder 12 which bears against an internal shoulder on the base element 6 constituted by an annulus 13 screwed into a counter-sinking of the hole in said base element 6 at the end towards the work-piece 7, and thus said circular inner element 3 is restrained against axial movement towards the work-piece. The concentric hole in the base element is also made conical and not cylindrical, the taper of saidhole being towards the workpiece 7. The circular outer element 5 has its outer periphery made conical to fit the conical hole in the base element 6 and its eccentric hole 4 made conical to fit the conical outer periphery of the circular inner element 3, and said circular outer element 5 is divided by means'ot a radial cut 14 (Figure 3) at the thinnest point of its circumference, so that it can be slightly expanded and contracted. It will thus be seen that if said circular outer element 5 is pressed axially towards the work-piece it will, by a wedge action, bind both with the circular inner element 3 and the base element 6 and thereby prevent rotation of both circular inner and outer elements S and 5. To press said circular outer element axially in this way, the end of the hole in thevbase element 6 remote from the work-piece 7 is countersunk, and an annular clamping ring 15 is screwed into the countersinking and adapted to engage a shoulder 16 (Figure 4) formed around the circular outer element.

For rotating the circular outer element 5 in the base element 6, said circular outer element has mounted on the upper surface thereof a plate 17 formed with a finger eccentrically in a circular outer element 5. Said circular outer element 5 is in turn rotatable in a hole formed concentrically in a base element 6 adapted to be mounted in fixed relation on the surface of the work-piece 7. In operation said base element 6 is first mounted in fixed relation on the surface of the work-piece 7 with the axis of the hole 2 in the circular inner element 3 close to a given point, and then, by adjustably rotating the circular outer element 5 in said base element 6 and said circular inner element 3 in said circular outer element 5, said axis can be brought accurately into coincidence with said given point. Then when the guide bush 1 is fitted into the hole 2 in the circular inner element 3 the axis of said guide bush will also be accurately in coincidence with said given point. During the adjusting operation a tubulug 18. Said plate 17 is secured in place on said circular outer element by means of a screw 19 which passes through a hole 20 in said plate and screws into a hole 21 in said circular outer element diametrically opposite to the cut 14. Two studs 22 on said circular outer element one each side of the screw hole 20 also engage in holes 23 in the plate 17. It will be seen that it is not necessary to provide the plate 17. with a cut corresponding to the cut 14.

For rotating the circular inner element 3 in the hole 4 in the circular outer element 5, said circular inner element has mounted on the upper end thereof a plate 24 formed with a finger lug 25. It will be seen that the upper end of said circular inner element 3 is slightly reduced'by machining, and that said plate 24 is of ring form and makes a force fit around said reduced upper end.

For rotating the clamping ring 15, the same has mounted on the upper end thereof a plate 26 formed with two diametrically opposite finger lugs 27. For securing said plate 26, the upper end of said clamping ring is slightly reduced by machining, and said plate 26 is of ring form and makes a force fit around said reduced upper end.

When said clamping ring 15 is rotated for unclamping the outer and inner circular elements 5 and 3 it engages the lug 25 which is attached to the inner circular elements 3 and thereby liftsboth said inner circular element and said outer circular element and free the latter from the base element 6. Said inner and outer circular element can then be freed 'from each other by means of the lugs. 18 and 25.

For mounting the base element 6 in fixed relation on the surface of the work-piece 7 said base element is formed with a concentric annular recess in which is mounted an electric winding 28, so that when said winding is energised, said base element constitutes the field element of an electromagnet and will'adhere firmly to the work-piece. Alternatively said base element 6 may be fitted with permanent magnets. In order that they shall not be aifected by the magnetism of said base element the circular inner and outer elements 3 and are made of non-magnetic metal and so also are the aforesaid annulus 13 and the clamping ring 15.

In practice the holes in the circular inner'and outer elements may be of equal eccentricity, say .060 of an inch. The angle of taper of the several conical surfaces may be about 5 degrees. The reference 29 designates a removable inner bush which fits in the bush 1. Inner bushes 29 of different internal diameters are employed according to the diameters of the drills to be guided.

The reference 30 designates the usual retaining screw for holding the bush 1 in place in the hole in the inner circular element '3. Th'ecut out 31 enables said bush 1 to be removed on loosening said screw 30. The reference 32 designates the junction box for the conductors to the winding 28. i

It will be clear that the invention is not limited to drill jigs, but can beapplied to anydevice in which fine adjustment is required in two dimensions over a given area. The invention could for instance be applied to gun sights.

I claim:

1. An indexing device for varying the position of a part in twddimensions relative to a work piece, said device comprising a base member attachable to said work piece and having a circular bore therethrough, an inner member having a circular outer periphery and a circularbore therethrough for receiving said part in said bore, an outer member having a circular outer periphery and a circular bore therethrough, said outer member being rotatably received in the bore of the base member and said inner member being rotatably received in the bore of the outer member, the axis of the bore in the inner member being eccentric with respect to the outer periphery of the said member and the axis of the bore of the outer member being eccentric with respect to the outer periphery of the said member, the outer periphery of said outer member and the bore in said base member being correspondingly conical and the outer periphery of said inner member and the bore in said outer member being rcrrespondingly conical, means for limiting axial movement of said inner member in one direction relative to said base member, the direction of the coming being such that axial pressure applied to said outer member in said one direction causes said outer member to bind both with said inner member and said base member, and a clamping ring in threaded relationship with said base member adapted to abut against said outer member and urge it into said one direction in response to a rotation thereof, whereby by rotating the inner member and the outer member relative to each other and the base member, the axis of the bore in the inner member may be positioned in coincidence with a selected point on the work piece.

2. A device according to claim 1, wherein the rim at one end of said circular bore in said base member is countersunk and threaded, and wherein said clamping ring is screwed in said countersunk end.

3. A device according to claim 2, wherein said clamping ring is provided with at least one finger operated lug.

4. An indexing device for varying the position of a part in two dimensions relative to a work piece, said device comprising a base member attachable to said work piece and havinga circular bore therethrough, an inner member having a circular outer periphery and a circular bore therethrough for receiving said part in said bore, an outer member having a circular outer periphery and a circular bore therethrough, said outer member being rotatably recived in the bore of the base member and said inner member being rotatably received in the bore of theouter member, the axis of the bore in the inner member being eccentric with respect to the outer periphery of the said member, and the axis of the bore in the outer member being eccentric with respect to the outer periphery of the said member whereby by rotating the inner and outer member relative to each other and the base member, the axis of the bore in the inner member may be positioned in coincidence with a selected point on the work piece,-said inner and outer members being respectively provided with finger lugs for eitecting rotation thereof, a clamping ring in threaded engagement with said base member adapted to be rotated into axial pressure engagement with said outer member and to bind the same both with said inner member and said base member, wherein upon unscrewing said clamping ring, said clamping ring engages the finger lug of said inner member and trees said inner member and outer member axially from said base member.

References Cited in the file of this patent UNITED STATES PATENTS 710,257 De Leeuw Sept. 30, 1902 1,565,264 Dubi Dec. 15, 1925 1,703,549 Sergeefi Feb. 26, 1929 2,146,906 Moller Feb. 14, 1939 2,381,943 Williams Aug. 14, 1945 2,424,485 Miller July 22, 1947 FOREIGN PATENTS 139,363 Great Britain Mar. 4, 1920 OTHER REFERENCES American Machinist, Self-Indexing Drill Jig, p. 156. April 27, 1953. r

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