US2870539A - Scribing implement - Google Patents

Description

Jan. 27, 1959 F. P. zAccoNE SCRIBING IMPLEMENT Filed April 2, 1958 IO/6 /I INVENTOR ATTORNEY United States A Patent 2,870,539 SCRIBING IMPLEMENT Frank P. ZaccorieyChicago, Ill.

Application April 2, 1958, Serial No. 725,816

8 Claims. I (CI. 33-41) -is readily useful for producing the line with a satisfactory degree of precision.

Another object of this invention is the provision of a geometrical scribing instrument having measuring means thereon as an aid for properly positioning the scribe point with respect to guide surface following components of the instrument so that a scribe line may thereafter be marked on the workpiece atthe intended distance of removal from the guide surface and having a direction consistent with the direction of the guide sur face.

Another object is the provision of a scribing tool of the character indicated which is well suited for laying down a line consistent with the dictates of a straight face or a curved face for a guide.

A further object is the provision of a scribing instrument which is equipped for marking a curved scribe line consistent with following an inside curve or an outside curve for guidance.

Another object of the invention is that of providing a scribing tool of the character indicated which is useful for such purposes as scribing a line on a horizontal surface at the base of a vertical guide surface or scribing a line on a horizontal surface above a vertical guide surface.

Other objects of the invention in part will be'obvious and in part pointed out more fully hereinafter.

In the accompanying drawing representing a preferred embodiment of this invention:

Figure 1 is a plan view of a scribing tool;

Figure 2 is a longitudinal sectional elevation of the tool as viewed along line A-A in Figure 1;

Figure 3 is a transverse sectional elevation of the instrument along line BB in Figure 1;

Figure 4 is a perspective view showing allocation of the guide following and marking portion of the scribing tool in working position at the base of a substantially vertical guide surface for laying down a scribe line on an adjoining horizontal surface;

Figure 5 depicts the guide following and marking portion of the scribing instrument in perspective relation to a workpiece affording outside curvature for guidance in the laying down of a scribe line on a substantially horizontal face of a workpiece; and

Figure 6 is a view similar to Figure 5 except that the scribing tool has guidance consistent with the dictates of an inside curved face of a workpiece.

- Like .reference characters denote like components throughout the several figures of the drawing.

As conducive to a clearer understanding of certain features of the present invention it may be noted at 2,870,539 Patented Jan. 27,1959

this point that scribing tools are in demand for such purposes as delineating in a precise manner lines which will serve for guidance in establishing points for boring, or to guide milling or sawing operations, or other machining functions which are to be performed along the path of the line. Scribers heretofore have been used in the machining of metal, in the woodworking field and in any of a variety of other endeavors such as fabricating synthetic sheet plastics. Usually the scribers are equipped with a marking component such as a hard steel point which is capable of producing a scratch line and sometimes the marking component is nothing more than a stick of graphite of the type ordinarily found in a lead pencil. The marking component ordinarily is adjustable with respect to work surface following contacts of the instrument so that it is thereafter possible to establish a scribe line at a desired marginal distance from the guide face of the workpiece. In such procedures as producing a series of spaced, bored apertures at a desired marginal distance from an edge of a workpiece, it is customary to scribe avline at the desired distance inward from the edge and thereafter by means of dividers or the like the center points of the apertures which are to be formed are marked along the scribed line. This geometrical layout work then is followed by simply boring the apertures in the workpiece at the center points. A

While many scribing tools are availablein the prior art, it has been diflicult with the use of these tools to achieve precise setting to establish the desired mark needed on the workpiece, considering too that a distance measurement is called for to establish the margin. Other scribing tools in the past have lacked facility for functioning in a variety of situations involving different shapes and contours of the workpieces which are to be scribed and therefore instead of having one tool with properties of wide utility a number of different scribing tools have been necessarily used to cover the various needs.

An outstanding object of the present invention accordingly is the provision of a scribing instrument which eliminates in a practical manner the need for supplemental marginal distance measuring for properly setting the scribe point in marginal relation to a guide surface, and which instrument is readily useful for inside and outside curved line scribing as well as for straight line scribing;

In accordance with the present invention a scribing instrument is provided for marking a line in accordance with the dictates of a guide surface of a workpiece or a supplemental pattern or guide and the instrument comprises a frame having spaced contacts for following the guide surface. A scribe bar is situated on the frame and is slidable in and out with respect to the frame along a path between the guide surface contacts of the frame. The scribe bar also has a contact and this contact is movable into abutment against the guide surface by sliding the scribe bar to a position which causes abutment to occur simultaneously with abutment of the frame contacts against this same guide surface. the scribe bar contact and the frame contacts into abutment against the. guide surface all at once a relative position accordingly is established between the several contacts which is consistent with the particular linearity of the guide surface. The instrument includes at least one scribe point on the scribe bar and also includes means on the heme and scribe bar for measuring the distance that the bar is to be moved to dispose the scribe point to a desired marginal position with respect to the guide surface. The measurement is based on scribe bar contact initially being set to a position relative to the contacts on the frame which corresponds to By bringing all of the contacts being against the guide surface at once. Thus it is easily possible for one to measure off with high precision any given marginal distance by reading the measuring means on the instrument itself and the scribe line may be satisfactorily laid down immedh ately after the setting is accomplished.

Referring now more particularly to the embodiment represented in the accompanying drawing reference numeral Ill generally designates a scribing instrument having a substantially U-shaped frame it and the outer ends of the legs of the frame are equipped with contacts 12 which are vertical tips of the legs of the frame and conveniently having length corresponding to the thickness of the frame legs. The leg ends diverge outward from the main body of the frame it so as to lend spread between contacts 12 and the inner faces 14 and 15 of the leg ends converge backward to a longitudinal slot 16 extending along the length of the frame and having substantially parallel inside faces 16a for purposes which will be described more fully hereinafter. The outer ends of the legs of frame ll are interconnected by means of a machine screw or bolt 17 which serves to some extent to adjust the separation of the legs and thereafter lends reinforcement against the relative position of the legs being altered once a esircd position of adjustment has been established. Screw 17, as shown in Figure 2 engages threads in upward lug extensions of the frame legs which at the same time lend thickness vertically to the frame contacts 12 of the instrument.

A substantially rectangular scribe bar 19 is disposed underneath the frame 11 so as to have a face slidably in abutment with the underneath face of the frame. Scribe bar 19 has mounted on its top surface a guide follower block 2% and the lateral dimensions of the follower sub stantially conforms to the width of slot 16 so that the washer 24 is disposed underneath the head of the wing screw 23 and overlaps the corresponding top surfaces of the legs of the substantially U-shaped frame 11. Thus by tightening this wing screw, it is possible to clamp and positively hold the scribe bar 19 and its guide follower to any desired setting longitudinally with respect to frame 11 along slot 16.

Scribe bar 1 .9, at the end adjacent to the frame contacts 12, itself has a guide surface contact point 25. Point 25 is a tip formed by uniformly beveling the end of bar 19 backward in opposite directions from the longitudinally center line of the bar. The opposite end of scribe bar 19, denoted end 26, projects outward beyond frame If so as to facilitate grasping and moving the bar longitudinally with the hand.

On the longitudinal axis of scribe bar 19 and at a known distance behind contact 25 of the bar is a scribe point 27 extending vertically through the bar and projecting downward beyond the underneath surface of the bar. Pads or legs of the instrument are threadedly engaged in tapped openings such as by shanks which extend adjustably into these openings. Preferably, there are two pairs of pads, one pair being the pads 28 which are situated on the legs of frame just behind contacts 12 of the frame. The other paid of pads, pads 29, are also on the frame legs but are disposed some distance behind those indicated by reference numeral 23. Conveniently, for ease of sliding the instrument, the lower ends of the pads have hemispherical faces and are shaped behind these faces to accommodate an adjusting wrench which will alter by adjustment the extent of projection of the pads beyond the underneath face of frame 11. The distance of projection of the pads may be set for the tips of the pads to be in a plane which is slightly behind the free end or marking end of the scribe point 27, thus for the scribe point to be operative for its marking function when the instrument is moved by sliding on the pad tips.

The instrument advantageously is equipped with guide surface contacts for frame 11 which may be attached and used in substitution for contacts 12. The substitute contacts, designated contacts 13, are cylindrical posts having at one end a reduced threaded shank 13a which correspond with threads in the apertures which receive the shanks of pads 28 and 29. The post contacts 13 may be substituted for either pair of pads 28 or the pair of pads 29 and are useful during such operations as are involved with Figures 5 and 6 of the drawing. Pads 28 and 2% are left in place When the instrument is used for certain scribing operations as for example the operations associated with Figure 4.

The top surface of one of the legs of the substantially U-shape frame 11 has a milled groove 36 extending parallel to the path of sliding movement of scribe bar 19 and this groove has slidably received in it a distance measuring scale 31. The scale is confined to groove 30 as by means of a leaf spring 32 screwed to the face of the frame 11 and overlapping the top surface of the scale, though the scale may be moved longitudinally against function. A finger piece 33 is attached to the outer end of the scale so that the scale can be more easily moved.

Mounted on guide follower 20 is an indicator 34 which overlaps the indicia of scale 31 and this indicator preferably alfords a width along the scale indicia which is equal to the distance between contact 25 of scribe bar 19 and the axis of scribe point 27. This arrangement makes it possible to set the scribe point 27 to a desired marginal position with respect to the frame contacts which are to be used against the workpiece which is to be marked.

The operation of instrument It) will be illustrated with reference to workpiece 35 in Figure 4, assuming that a scribe line 36 is to be put down on the substantially horizontal portion of 35a of the workpiece at a given distance from the inner vertical face 35b of the piece. For this marking, pads 28 and 29 are kept in place. Instrument 10 is brought to the position indicated in Figure 4 with the frame leg contacts 12 in abutment against surface 35b. Wing screw 23 is loosened and scribe bar 19 and its guide follower 20 are subjected to sliding movement in frame 11 until contact point 25 of the bar also abuts face 35b of the workpiece. Wing screw 23 then is tightened down to clamp scribe bar 19 to frame 11. With the scribe bar clamped, scale 31 is moved until a suitable one of its distance indicating lines is brought to a so-called zero, or basis of measuring position, with respect to side D (see Figure 1) of indicator 34. Then wing screw 23 is loosened and slide bar 19 is advanced to the left in Figure 1 until the marginal distance desired of scribe line 36 from face 35b of the workpiece can. be read on side E of indicator 34 on the measuring scale 31 thus compensating for the distance of set-off of scribe point 27 from the bar contact 25. The distance measured is based on the so-called zero position already established on the scale. Then, wing screw 34 is turned to lock scribe bar 19 to frame 11 once more. By placing instrument 10 in the position indicated in Figure 4 and sliding the instrument on pads 28 and 29 with the contacts 12 constantly maintained in abutment against face 35b of the workpiece, scribe line 36 accordingly is actually laid down by the scribe point 27. A similar set of operations is performed in producing scribe line 37 on the substantially horizontal face 38 in Figure 5, using outside cylindrical face 39 of the workpiece for guidance. In this instance, however, pads 29 have been removed and cylindrical contacts l3 have been substituted to serve as contacts on frame 11 in lieu of conis brought to so-called zero position with respect to side E of the indicator and scribe bar 19 then is moved until the desired marginaldistance of scribing from face 39 of the workpiece is readable on side D, thus compensating for the distance between scribe point 25 and contact 27.

Whenusing implement for scribing a line based on an inside curve of a workpiece for a guide, a different slide bar contact other than contact 25 sometimes is introduced. This conveniently is a vertical pin 40 which is threaded vertically into the underneath side of slide bar 19 along the longitudinal axis of the bar on the opposite side of scribe point 27 from contact 25. Pin 40 as shown is a cylindrical pin and its face nearest end 26 of the slide bar is at the same known distance from scribe point 27 as is contact 25. Pin 40 may :be readily removed, such as by having a screw driver slot on its outer end, so as to be out vof the way when contact 25 is needed for use.

Figure 6 will serve to illustrate the operation of instrument 10 in scribing a line 41 using an inside cylindrical vertical face 42 of a workpiece for guidance. Line 41 is to be put on a substantially horizontal face 43 of the workpiece. Wing screw 23 first is loosened and contacts 13 of the frame are pressed against guide face 42 and so is the face of the contact pin 40 of the scribe bar. With corresponding faces of frame contacts 13 and bar contact 40 in abutment with face 42 wing screw 23 is tightened to maintain this relative position of the contacts. Scale 31 then is moved to bring one of its scale marks into zeroing registration with side B (see Figure l) of indicator 34. Wing screw 23 then is loosened and slide bar 19 is moved longitudinally until the desired distance of scribe line 41 from face 42 is readable at side D of the indicator 34. The distance is read from the selected zero point on the scale but by finally reading the scale on the side D of the indicator the distance between scribe point 27 and contact 40 of the slide bar is compensated for and accordingly the intended distance which scribe line 41 is to be from face 42 of the workpiece is set. Wing screw 23 is tightened to maintain the setting. Then, with instrument 10 situated in the Figure 5 position, and contact 40 removed, scribe line 41 is accurately put in place using contacts 13 as followers against face 42.

Instrument 10 also is useful scribing straight lines while being made to follow a straight guide surface. Depending upon which contact of slide bar 19 is used, this being either contact or contact 40, the instrument thereafter is properly set with the use of scale 31 and indicator 34 and while using the scale and indicator to compensate for the distance of the scribe point from the bar contact.

Thus it will be seen that with this invention the various objects noted herein together with many thoroughly practical advantages are successfully achieved. It will be seen that the instrument is well suited for scribing and that it offers facility for setting the scribe point to any of a variety of positions based on reading a scale which enables a proper scribing relation of the components of the instrument to be derived.

While in the preceding description the single scribe point has been mentioned, it will be distinctly understood that the scribe bar may have several scribe points at predetermined distance or distances along its length, it being possible to set any particular one of those points by knowing the distance between them. The instrument likewise may lend itself to accommodating one scribe bar in substitution for another scribe bar so as to introduce different scribe points and bars having differently positioned scribe points better suited for particular need.

As many possible embodiments may be made of the invention and as many possible changes may be made 6 of the embodiments hereinbefore set forth, it will be distinctly understood that all matter described herein is to be interpreted as illustrative and notas a limitation.

I claim: 1. A scribing instrument for marking a line in accordance with dictates of a guide surface of a workpiece or the like, said instrument comprising a frame having spaced contacts for the instrument to follow the guide surface, a scribe bar on said frame and slidable with respect to said frame in and out along a path between said contacts, said scribe bar itself having a contact for the guide surface and being slidable with said bar to a position relative to the contacts on said frame corresponding to all of said contacts being against said guide surface at once, a scribe point on said bar, and means on said frame and scribe bar including a scale and an indicator for said scale individually on said frame and scribe bar for measuring the distance said scribe point is set for scribing with respect to said guide surface subsequent to said contact on said slide bar being set to a position relative to the contacts on said frame corresponding to all of said contacts being against said guide surface at once, said scale and indicator being movable with respect to each other while said contacts are in positions equivalent to being against said guide surface all at once.

2. A scribing instrument for marking a line in accordance with the dictates 'of a guide surface of, a workpiece or the like, said instrument comprising a frame having spaced contacts for the. instrument to follow the guide surface, a scribe bar on said frame and slidable with respect to said frame in and out along a path between said contacts, said scribe bar itself having a contact for the guide surface and being slidable with said bar to a position relative to the contacts on said frame corresponding to all of said contacts being against said guide surface at once, a scribe point on said bar and spaced longitudinally of said bar a predetermined distance from the contact of said bar, a measuring scale and an indicator for said scale, said scale and indicator being relatively movable for applying one to the other an indicated distance of relative offset equal in amount to the distance between the scribe point and scribe bar contact and for measuring the distance the scribe point is from the guide surface.

3. A scribing instrument for marking a line in accordance with the dictates of a guide surface of a workpiece or the like, said instrument comprising a frame having spaced contacts for the instrument to follow the guide surface, a scribe bar on said frame and slidable with respect to said frame in and out along a path between said contacts, said scribe bar itself having a contact for the guide surface and being slidable with said bar to a position relative to the contacts on said frame corresponding to all of said contacts being against said guide surface at once, a scribe point on said bar and spaced longitudinally of said bar a predetermined distance from the contact of said bar, and means including a slidable scale and an indicator for said scale individually on said scribe bar and frame, said indicator presenting a Width to said scale corresponding to the distance existing between the contact of said scribe bar and said scribe point, whereby said slidable scale may be zeroed on one side of the width presented by said indicator and read at the other side of that width to compensate for the effective distance between the scribe point and the bar contact after said scribe bar has been set to a position relative to the contacts on said frame corresponding to said bar contact and said frame contacts being against said guide surface at once.

4. A scribing instrument of the character set forth in claim 3, in which said frame is a substantially U-shaped member and said frame contacts are at the outer ends of the legs of said U-shaped member, in which said scribe bar overlaps corresponding outside faces of said legs and is guided by a guide follower situated between the legs of said member and said follower in turn is guided by the inside faces of said legs, said scribe bar being movable back and forth between said frame contacts under the guidance of said guide follower and the inside surfaces of said legs, and in which manually operable set screw means has a set screw connected with said scribe bar and overlaps corresponding outside faces of said legs on the side of said U-shaped member opposite from the outside surfaces of the legs overlapped by said scribe bar for locking said scribe bar in position against sliding with respect to said frame.

5. A scribing instrument for marking a line in accordance with dictates of a guide surface of a workpiece or the like, said instrument comprising a frame having spaced outside contacts for the instrument to follow the guide surface, a scribe bar on said frame and slidable with respect to said frame in and out along a path between said contacts, a scribe point on said scribe bar, said scribe bar itself having along its length contacts on opposite sides of said scribe point each at the same distance longitudinally of said bar from the scribe point as the other for selective use and either of said bar contacts used being slidable with said bar to a position relative to the contacts on said frame which corresponds to said frame contacts and the selected base contact being against said guide surface at once, means for locking said scribe bar in position against sliding with respect to said frame, and means including a slidable scale and an indicator for said scale individually on said scribe bar and frame, said indicator presenting a width to said scale corresponding to said effective distance between the scribe point and the selected one of the contacts of said scribe bar and said scribe point, whereby the slidable 6; scale may be zeroed at proper side of the width of said indicator and read at the other side of said width to com pensate for the distance between the scribe point and the selected bar contact after said scribe bar has been set to a position relative to the contacts on said frame corresponding to said selected contact and said frame contacts being against said guide surface at once.

6. A scribing instrument of the character set forth in claim 5, in which said scribe bar has an end tip serving as one of its contacts and the other of its contacts for selective use on the other side of said scribe point is a detachable contact.

7. A scribing instrument of the character set forth in claim 5, in which said frame is a substantially U-shaped member, said frame contacts being at the outer ends of the legs of said U-shaped member, and in which said scribe bar is attached to and guided by a guide follower situated between the legs of said frame, said scribe bar having an end tip for a contact adjacent to said frame contacts and the other of said bar contacts for selective use on the other side of said scribe point being a detchable contact.

8. A scribing instrument of the character set forth in claim 7, comprising posts secured to the frame legs demountably, whereby said posts and the tip ends of said legs are usable selectively as said contacts.

References Cited in the file of this patent UNITED STATES PATENTS 915,219 Regelson Mar. 16, 1909 FOREIGN PATENTS 587,346 Great Britain Apr. 22, 1947

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