US2791031A - Apparatus for projecting circular markings upon curved surfaces - Google Patents

Description

May 7, 1957 J. A. USKERT 2,791,031

APPARATUS FOR PROJECTING 'CIRCULAR MARKINGS UPON CURVED SURFACES Filed April 6, 1-954 2 Sheets-Sheet 1 UIIIIIIIIIIIII.flUI/IIIIIIA V/IIIIIIIIIIIIIIIII INI ENTOR.

J. A. USKERT 2,791,031

APPARATUS FOR PROJECTING CIRCULAR MARKINGS upon CURVED SURFACES May 7, 1957 2 Sheets-Sheet 2 Filed April 6, 1954 United States Patent V I APPARATUS FOR PROJECTING CIRCULAR MARKINGS UPON CURVE!) SURFACES Julie A. Uskert, Gary, Ind.

Application April 6, 1954, Serial No. 421,279

2 Claims. C1. 33-41) This invention relates to geometrical instruments and more particularly to a scriber for projecting circular markings upon curved surfaces.

In the past whenever it was necessary to fit a pipe into a tank or into another pipe having curved or multiplanar surfaces, the projection of the circular pipe upon the curved work surface was made by trial or error or by rough approximation. The result being that fittings were not exact and a great deal of time and effort were required.

Therefore, it is an object of this invention to provide an apparatus of relatively simple construction and capable of economical manufacture which is capable of projecting a circle of predetermined diameter upon a curved surface so that the pipe or other circular fitting to be inserted into the opening out along the marl: made by the present apparatus will have an exact fit with a minimum amount of effort and the elimination of the previous trial and error methods.

It is another object of this invention to provide an apparatus for scribing a projection of a circle upon a curved surface which may be releasably attached to the curved work surface upon which the circular projection is to be scribed, thus eliminating the need for any type of pilot hole to be drilled through the curved surface as a guide for the apparatus and eliminating the requirement for fixedly securing the apparatus to the curved work surface as is necessary with previously known instruments for this type of operation.

It is yet another object of this invention to provide a geometrical instrument for scribing a projection of a circle upon curved surfaces which is capable of selective adjustment with respect to the angular disposition of the apparatus with respect to the vertical center line of the curved work surface, or in the case of a pipe or tank, with respect to the transverse or diametric axis thereof.

Other objects and advantages will become apparent from a consideration of the following detailed description, forming the specification, and taken in conjunction with the accompanying drawings, in which:

Figure 1 is a front elevational viewof the apparatus embodying this invention as applied to a curved work surface;

Figure 2 is a sectional view taken along line 2-2 of Figure 1;

Figure 3 is a vertical cross sectional view taken along line'3-3of Figure 1;

Figure 4 is a sectional view taken along line 4- 4 of Figure 3 showing the protractor at the top center of the curved work surface;

Figure 5 is a transverse cross sectional view taken on line 5-5 of Figure 1;

Figure 6 is a cross sectional view taken on line 6=-6 of Figure 3; i

Figure 7 is a cross sectional view taken on line 7 7 of Figure 3; I

Figure 8 is a cross sectional view taken on line 8-8 of Figure 3;

Patented May 7, 1957 Figure 9 is a fragmentary cross sectional view through a curved surface in which an opening has been cut in accordance with the marking inscribed thereon by the apparatus of this invention and showing a circular or cylindrical body received through the opening in the curved surface;

Figure 10 is a view similar to Figure 3 but showing only the lower end of the post and the protractor carried thereby with the post at a predetermined angle with respect to the perpendicular center line through the top center of the curved work surface; and

Figure 11 is a fragmentary view in cross section showing a modified form of the attaching means for the apparatus.

With continued reference to the drawings, there is shown a geometrical instrument, generally indicated at 10, which is an apparatus for scribing circular projections upon curved surfaces, The apparatus 10 includes in its construction an upstanding post 12 having its lower end tapered as at 14 which defines a point adapted to engage-in a punch mark made in a curved Work surface '16 to indicate the desired center of an opening to be made throughthe work surface for receiving a circular body therein. The work surface 16 may be the curved w'allof a tank or pipe into which another pipe or circular body is to be fitted.

A scale arm guide, generally indicated at 18, iscarried by the post 12 for sliding movement longitudinally thereofintermediate its ends. The guide 18 includes a sleeve 20 which is freely slidable longitudinally of the post 12 and carries'intermediate its ends a hollow cylindrical tube or pipe 22 which extends with its longitudinal axis normal to the longitudinal axis of the sleeve 20, hence the axis of the tube is also normal to the axis of the ost 1 2. A scale arm 24 in the form of a tubular rod having inscribed thereon units of lineal measure 26 and slidably'carried by the tube 22 in the bore therethrough for movement in 'a rectilinear path through the guide 18 perpendicular to the post 12. Lock means in the form of a wing bolt 28 is carried by the tube or pipe 22 adjacent one end thereof in a suitably threaded opening therethrough communicating with the central bore of the tube whereby the scale arm, defining, a beam, may be selectively secured in its rectilinear path of movement through the :guide 18 and specifically through the tube or pipe 22thereof.

A collar 30 is slidably mounted on the .post 12 and disposed between the guide 18 and the pointed end 14 of the post,- and collar 30 carries lock means in the form of a wing bolt or nut 32 whereby the collar can be secured in any desired position along the length of the rod 1 2 between the pointed end 14 and the guide 18. The collar 30 acts as astop means to limit the downward movement of the scale arm guide 18 on the post 12, and the stop collar 30 is adjustable longitudinally of the post 12 so that the position of the guide lfirnay be selectively predetermined along the longitudinal extent of the post 12.

With the tapered or pointed end 14 of the post 12 in engagementwith the punch mark 15 in the work surface 16, the inst inent or apparatus 10 is provided with attachin'g'meansror releasabl'y securing it on the curved work surface 16. This attaching means comprises a'plurality of arms 34, 36 and 38, each of which carries at one 'end a magnet 40 which is pivotally attached to the adjacent end 'of the respective arm. The other end of the arm 34 remote from the end upon which a magnet '40 is 'pivotally connected, is pivotally secured between 30. The collar 46 may be fixed in a stationary position 1 upon the post 12 by a wing bolt or nut 48 carried therer by, which when tight willengage the post 12 to secure the collar 46 in a fixed position longitudinally of the'post.

Another collar 50,,somewhate similar to the collar 46, has formed thereon angularly spaced pairs of spaced, parallel, laterally projecting ears 52 and 54 to receive therebetween the ends of the arms 36 and 38 respectively. A rivet 56 passes through transversely aligned openings in the ears 52 and an aligned or registering opening in the arm 36 adjacent the end thereof remote from the magnet 40 so as to pivotally secure the end of the arm to the collar 50. Similarly, a rivet 58 is received through transversely aligned openings in the ears 54 and through a registering opening in the arm 38 adjacent its end remote from the end which pivotally carries the magnet 40 so that the arm 38 is pivotally connected to the collar 50 and extends laterally therefrom, in similar manner to the manner in which the arms 34 and 36 also laterally project from their respective collars. This structure is clearly shown in Figure 8.

Thus, by properly adjusting the collars 46 and 50, the collar-50 being slidably mounted on the post 12 and adapted to be secured therealong in a fixed position by a Wing bolt 60, and the arms 34, 36 and 38 extended outwardly and downwardly therefrom so that the magnets carried at the ends of the respective arms contact the curved surface 16,will releasably secure the apparatus thereon, assuming that the material of the curved work surface 16 is of the magnetic type.

If, however, the work surface 16 is of a non-magnetic material, then a vacuum cup, such as the vacuum cup 62 as shown in Figure 11, may replace in the holder 41 which is pivotally secured to the ends of the respective arms remote from the collars 46 and 50 respectively. The vacuum cup 62 may be secured in the respective holders 41 by a screw 64 in the manner shown in Fig ure 11.

It will be noted that the collar 50 carrying the arms 36 and 38 is disposed between the collar 46 on the post 12 and the pointed or tapered end 14 of the post.

One end 66 of the scale arm 24 carries a guide sleeve 68thereon. The guide sleeve 68 is secured to the end 66 ofthe scale arm 24 as by being riveted thereto centrally intermediate its ends and has its axis disposed normally to the longitudinal axis of the arm 24. A scriber 70 is received in the bore 72 of the guide sleeve 68 and is freely movable therethrough in a rectilinear'path parallel to the post 12 but spaced therefrom.

The upper end of the scriber 70 is provided with an enlarged circular head 74 of greater diameter than the bore 72 so that the scriber 70 cannot pass entirely through the guide sleeve 68, and in addition provides additional weight to urge the scriber downwardly through the bore 72 of the guide sleeve 68 toward the, curved surface of the work piece 16. The lower end, or end remote from the head 74, carries thereon a hollow cylindrical holder 76 having springs 78 disposed within the bore thereof and extending longitudinally of the bore so as to resiliently grip a marking instrument 80 therein, the pointed end of the marking instrument, which may be a pencil or soap stone or other means whereby a mark may be inscribed upon the surface 16, projects outwardly from the end of the holder 76 remote from the end thereof secured to the scriber 70.

Thus, the scriber 70 is carried by the scale arm 24 in spaced relation to the post 12 and is movable with the arm as the arm is moved in a circular path perpendicular to the post. The movement of the arm 24 in the circular path normal to the post 12 is possible since the sleeve 20 is freely rotatable about the post 12 and rests upon the adjacent-face of the stop collar 30 which defines a bearjug surface. a

Therefore, to scribe a circular projection upon the curved work surface 16, a punch mark is made in the work surface 16 to indicate the center of the circular projection to be scribed thereon and the pointed or tapered end is engaged in the punch mark 15. In order to insure that the post 12 is in proper vertical alignment with the vertical center line through the punch mark 15, and hence the center of the circular projection to b inscribed upon the curved surface 16, the post 12 is ad justed until the bubble in the bubble type level 82 carried on the tube 22 is centered therein. With the post 12 properly oriented in a vertical position as indicated by the level 82, the arms 34, 36 and 38 are then disposed so that the magnet 40 in the case where the material of the work piece is magnet, or the vacuum cups 62 in the case where the material of the work piece is non-magnetic, contact the outer surface of the Work piece to releasably secure the apparatus 10 thereon. It will be appreciated that the collars 50 and 46 may be suitably adjusted longitudinally of the post 12 so as to have the arms extend therefrom in such manner as to afford the best attaching contact with the surface of the work piece 16. The nut 28 may then be loosened as to permit the scale arm or beam 24 to be moved through the scale arm guide 18 in a rectilinear path perpendicular to the post 12 and thereby move the scriber 70 carried by the arm or beam 24 to a predetermined distance in spaced relation to the post 12. The scale defined by the units of measure 26 on the arm 24 will indicate the distance between the center lines of the post 12 and scriber 70. In order to aid in determining quickly and accurately the distance between the scriber and the post, a rectangular opening 84 is provided through the side wall of the tube 22 centrally intermediate its ends and generally along the longitudinal axis of the post 12, to define a window through which the different ones of the units of measure 26 may be visually perceived. Thus, the distance may be readily and accurately determined between the scriber 70 and the post 12, and then the set screw or wing bolt 28 tightened to fix the selected distance between the scriber and the post. The arm or beam 24 is then moved in its circular path and the scriber 70 is moved therewith thereby causing the point of the marking instrument to mark or inscribe the projection of the circular path of predetermined diameter upon the curved surface of the work piece 16. With the marking inscribed on the work piece, the apparatus 10 is removed from the Work piece, and the work piece is cut along the inscribed mark to define a generally elliptical opening 86 therethrough to receive therein with a tight fit a circular pipe or other circular body 88, as shown in Figure 9.

Where the opening through the curved work piece 16 is to be cut at an angle with respect to the vertical center line through the top center of the curved work piece, the

protractor 90 is set along the vertical center line through the top center of the worker pipe or tank through which the opening is to be cut, with the center line coincident with the vertical or ninety degree reading on the protractor scale 91. The protractor 90 is operatively connected to the post 12 of the apparatus 10 by a collar ,92 slidably mounted on the post 12 adjacent its lower or pointed end 14 and fixedly securable thereon by means of a wing-headed set screw 94. The collar 92 has formed thereon a threaded shaft 96 which projects outwardly therefrom perpendicular to the axis of the bore of the collar and in a direction away from the direction in which the set screw 94 extends, or to the side of the collar opposite to the side which carries the set screw 94. The shaft 96 extends transversely through an arcuate slot 98 formed in the body of the protractor 90 and concentric with the scale 91, and a nut 100 is threadedly received on the end of the shaft 96 projecting through the slot 98 so that the protractor 90 will be brought in face to face engagement with the collar, defining a sliding clamp for the protractor, so that the protractor is frictionally engaged against the adjacent face of the collar and restrained from movement. However, it will be apparent, that by loosening the nut 100, the post 12 may be inclined either to the right or to the left of the vertical center line through the top center of the work piece 16, as viewed in Figures 3 and 4 and Figure 10, and secured at any desired angular disposition as indicated on the scale 91 by again tightening the nut 100. The scribing operation will then proceed in the manner hereinbefore described with the scriber 70 set at a predetermined distance from the post 12 so as to project a circle of predetermined diameter upon the curved surface of the work piece 16.

It will be apparent that, with the apparatus inclined from its vertical position, the attachment means whereby the apparatus may be releasably secured upon the Work piece 16, will be appropriately adjusted longitudinally of the post 12, as well as the stop collar 30 and scale arm guide 18 being suitably adjusted longitudinally of the post 12 in order to facilitate the subsequent scribing operation.

It is pointed out, that as the scriber 70 is moved in a circular path about the longitudinal axis of the post 12 as the axis of rotation, to the broken line position shown in Figure 2, the apparatus or instrument It) will be maintained in its proper, pre-selected angular relation to the curved surface of the work piece 16 by the attaching means carried by the post 12 and which are adjustable longitudinally thereof.

From the foregoing, it will be apparent that there has been provided an apparatus for scribing circular projections upon curved surfaces, which comprises an upstanding post having its lower end engaging a curved surface upon which the projection of a circle is to be scribed, an arm guide 18 carried by the post 12 intermediate its ends for movement in a circular path perpendicular to the post, an arm carried by the guide for movement in a rcctilinear path which lies perpendicular to the post 12, attaching means carried by the post for selective adjustment longitudinally thereof to releasably secure the post upon the curved surface, and a scriber carried by the arm 24 in spaced relation to the post 12 and movable along with the arm 24 and guide 18 in its circular path to mark the projection of a circle upon the curved surface. Hence, it will be seen that the scriber 70 is carried by the post 12 for movement in a circular path about the post as an axis.

While there are shown and described the preferred embodiment of the invention, it is to be understood that the structure is susceptible to change and modification within the practicability of the invention and therefore should be limited only by the scope of the claims appended hereto.

What is claimed is:

1. An apparatus for scribing circular projections upon curved surfaces, comprising an upstanding post having its lower end engaging a curved surface upon which the projection of a circle is to be scribed, an arm guide carried by said post intermediate its ends for movement in a circular path perpendicular to said post, an arm carried by said guide for movement in a rectilinear path which lies perpendicular to said post, attaching means carried by said post for selective adjustment longitudinally thereof to releasably secure said post upon the curved surface, and a scriber carried by said arm in spaced relation to said post and movable with said arm in its circular path to mark the projection of a circle upon the curved surface, said attaching means comprising a first collar, an arm pivotally connected at one end to said first collar and pivotally carrying at its other end means detachably securable upon the curved surface, a second collar, a pair of angularly spaced arms, each of said pair of arms being pivotally connected at one end to said second collar and means detachably securable upon the curved surface pivotally carried at the other end of each of said pair of arms.

2. An apparatus for scribing circular projections upon curved surfaces, comprising a post having one end in engagement with a curved surface upon which the projection of a circle is to be scribed, a scriber carried by said post in spaced relation thereto for movement in a circular path about said post as an axis, said scriber also mounted for movement in a rectilinear path parallel to said post, and attaching means carried by said post for selective adjustment longitudinally of said post and detachably securing the post upon the curved surface, said scriber marking the projection of a circle upon the curved surface as it is moved in its circular path, said attaching means comprising a first collar, an arm pivotally connected at one end to said first collar and pivotally carrying at its other end means detachably securable upon the curved surface, a second collar, and a pair of angularly spaced arms, each of said pair of arms being pivotally connected at one end to said second collar and means detachably securable upon the curved surface pivotally carried at the other end of each of said pair of arms.

References Cited in the file of this patent UNITED STATES PATENTS 988,188 Graham Mar. 28, 1911 994,665 Weimer June 6, 1911 2,497,853 Arnold et al. Feb. 21, 1950 2,594,457 Kunzler Apr. 29, 1952 2,612,695 Schneider Oct. 7, 1952 2,659,972 Norris Nov. 24, 1953 FOREIGN PATENTS 511,875 Germany Aug. 22, 1931 OTHER REFERENCES Goddard: Peculiar Curved-Surface Intersections Scribed Easily, American Machinist magazine, September 12, 1946, page 144.

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