US2638677A - Sine bar - Google Patents

Description

May 19, 1953 A. H. sHERlFF -2,638,677

SINE BAR Filed April 2l 1950 ATTO? NEYS.

IN VEN TOR. 41. BER r SHE/WF1;

UNITED STATES i PATENT OFFICE SINE BAR Albert H. sheriff, Covington, Ky.

Application April 21, 1950, Serial No. 157,298

This invention relates to a sine bar which is, generally speaking, a precision instrument used by tool and die makers for measuring and setting up angles with great accuracy. Since the uses of a sine bar are well known to one skilled in the art they will not be set forth in detail herein.

An object of the present invention is to provide a sine bar which is more universal than sine bars heretofore available and to provide a sine bar which can be used in a `variety of positions with equal accuracy. It is another object of the invention to provide a sine bar which is 4capable of extremely accurate and delicate adjustment and which can be tightly clamped in any desired position of adjustment without affecting the adjustment thereof.

The advantages above set forth :and others which will be set forth hereinafter or which will become apparent to the man skilled in the art upon reading these speciiications I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplarl7 embodiment.

Reference is made to the drawings forming a part hereof and in which:

Figure 1 is a plan view of a sine bar according to my invention.

Figure 2 is a front elevational view of the same.

Figure 3 is an end'elevational view of the same.

Figure 4 is a cross sectional view on an enlarged scale taken on the line 4-4 of Figure 1.

Figure 5 is a view similar to Figure 4 but showing the parts in exploded condition.

Figure 6 is a fragmentary perspective View of the outer end of the blade showing a spacing block which may be used.

Briefly, in the practice of my invention I `provide a basic block and a blade pivoted thereto. The block will be accurately machined on all sides and will have a semi-circular end. A blade member will be pivoted on the center of the semicircle at the semi-circular end, and the blade will be of exactly the same width as the basic block. and therefore of the same width as the diameter of the semi-circle. The blade will have secured to it at a denite distance from the pivot point a disc which will be of a diameter equal to the width of the blade. This structure is well known in sine bars. The present invention relates to improvements in specific details of structure, as will now be set forth.

In Figure 1 the basic block is indicated at I0. It is machined so that its edges are all square with respect to each other and so that its opposite sides are parallel. At one end it will termi- 3 claims. (o1. 3'3-115) `2 nate in aisemi-circular configuration, as shown in Figures 1, 2 and 3 at II. The semi-circle II will be drawn about the point I2 (Figure 1) so that the diameter of the semi-circular portion I I will be exactly equal to the width of the block I il. Pivotally secured to the block IU is a blade I3 which is of -a width exactly equal to the width of the block I il and therefore also equal to the diameter of the semi-circular portion II. The point lf2 mentioned above is the pivot point of the blade I3 with respect to the block i2. The 'blade I3 carries at an accurately determined distance from the point I2 a disc I4, which disc is also of a diameter exactly equal to the width of the blade I3. The distance between the pivot point I2 and the center I5 of the disc I4 is some accurately measured distance such as, for example, ten inches. Ten inches is a desirable value because it facilitates .the use of this device with a table of sines.

Referring now in more detail to Figures 4 and 5, I shall describe the manner of assembling the block I Il and the blade I3.` The block I is provided with a hole 2|) having a keyway 2I and a counterbore at 22. The blade I3 is provided with a hole 23 of the same diameter as the hole- 2 and a washer 2li is arranged between the block I0 and the blade I3. The washer 24 also has a hole 25 of the same diameter. A knurled disc 26 is provided with a hole 2l of the same diameter which is counterbored as at 28. The disc I26 is provided with Spanner holes at 29. The parts thus far described are held in assembled relation by cooperation between the threaded stud 3D and the nut 3|. The stud 30 h-as a shank 33a of a diameter to lit snugly the holes 2li, 23, 25 and` 2l, and it is provided with a key 32 arranged to engage in the keyway 2l; but the key 32 is spaced from the ange 33 of the stud so that, as `best seen in Figure 4, the key 32 engages in the keyway 2| of the member Il! and clears the washer 24. The nut 3l has a central boss 34 of a diameter to t the bore 23 `and is internally threaded at 35 for engagement with the threads 36 of the stud 3D. The main diameter of the nut 3| is such as to fit snugly within the counterbore 22, and the thickness of the nut 3l is such that it 'ts flush with the surface of the block IIJ. Similarly the llange 33 ts flush within the counterbore 28.

By virtue of the construction described the nut 3l may be tightened without disturbing the setting of the blade I3 with respect to the block I0. A Spanner wrench is provided as shown in broken lines at 31 in Figure 5 and has the studs 3B which may be engaged in the Spanner holes 38' in the nut 3I or in the spanner holes 29 of the knurled disc 26. The engagement between the key 32 and the keyway ZI effectively prevents relative rotational movement between the stud 39 and the block I9. Thus, when the nut 3| is tightened, the stud 39 is simply drawn into the block I9 longitudinally and with no twisting movement. Therefore the disc 28 simply exerts pressure against the blade i3 and through the washer 2li against the block I9 without disturbing any angular setting which may have been made.

To facilitate quick setting the blade I3 may be provided with an index 119 (Figure 3) and the semi-circular portion of the block I9 may be provided with markings 4I which may be in degrees if desired so that a preliminary rough vsetting may be made by simply aligning the index '49 with the suitable graduations on the scale 4I. The graduations on the scale 1I will run both ways from a zero position so that angles in either direction may be set up. The nut 3l may then be partially tightened and fine adjustment may be accompiished by movement of the knurled disc 2t which is in frictional engagement with the blade I3. If the clamping action is fairly tight, and a minute adjustment is desired, the Spanner wrench 31 may be applied to the knurled disc 26 and in this way very minute adjustments of the blade I3 with respect to the block I9 may be made. When the desired angle has been set up, as by the use of a gauge block in connection with the disc I4 and a reference surface upon which the block I9 rests, the nut 31 is finally tightened and will hold the parts ii'rmly in the desired position.

Since all surfaces of the block I9 and the blade I3 have been accurately machined, the sine bar according to the present invention may be used in any position. t may even be used upsidedown from the position shown in Figures 2 and 3, since the thickness of the disc I9 and the thickness of the knurled disc 29 are identical. However, it will generally be used either in the position shown in Figures 2 and 3 or in `a position like that of Figure l, if Figure 1 were an elevational view.

When the blade I3 is widely opened there will be an overbalancing tendency In order to avoid this diiiculty provide a separate block in the nature of a foot and indicated in Figure 6 at 46.2. The block i2 is provided with a slot 93 having walls parallel to the end walls of the block 42, and the slot i3 will be exactly the thickness of the blade 13 and will be spaced from one end of the block l2 in the same way as the blade I3 is spaced from the bottom surface f the block Il), as seen in Figure 2. Thus, the slot 43 wili be at adistance a from one end of the block, corresponding to the distance a as shown in Figure 2, so that if the device is used in the position of Figure 2, the block i2 may 'be slipped on as shown in Figure 6, and it will support the blade in its over-hanging position. If the device is used in the upside-down position, the slot @3a will be used, and will be engaged with the block I9 which it fits snugly. from one end of the block I2 by a distance h corresponding to the distance b as shown in Figure 2, so that the block i2 will support the block I9 horizontally. If desired, threaded holes may be provided in the block t2, and aA thumb-screw 441 1n this case the slot 93a is spaced` '4 may be used to clamp the block to the blade I3 or the block IIJ.

In order that the sine bar of my invention may be used in a lathe or the like between centers, I have provided the center holes 59, 5I on the longitudinal centerline of the block I0.

I have not discussed the uses of the sine bar since the uses are well known to any tool and die maker. The advantages of the present tool will be obvious to those skilled in the art who will know how to use it without further instructions. It will be clear that numerous modiiications may be made without departing from the spirit of my invention, and I therefore do not intend to limit myself, except as set forth in the claims which follow.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is:

l. In a sine bar comprising a block and a blade, a pivoting and 'clamping assembly therefor comprising a thin washer between said block and blade in the pivoting area, a threaded stud and a nut, said blade and biock having a hole to accommodate snugly said stud, key means for preventing relative rotation between said stud and said block, said block having a counterbore, said nut having a diameter and thickness to Afit snugly and flush within said counterbore, and a knurled disc having a hole to accommodate snugly said stud, said disc `having a counterbore and said stud havingv a ange of a diameter and thickness to seat snugly and fiush within said last named counterbore, sai-d disc bea-ring frictionally against said blade, and saidl nut bearing against said block.

2. The structure of claim 1, wherein said nut and said knurled disc are provided with Spanner engaging abutments.

The structure of claim 1, wherein said nut has a portion of a diameter tol extend snugly into the hole insaid block.

ALBERT H. SHERIFF.

References Cited in the i'ile of this patent UNITED STATES PATENTS Number Name Date 450,323 'Fuller Apr. 21, '1891 592,050 lLantz Aug. 8, 1893 593,987 press Nov. 23, i897 594,607 Davis Nov. 30, 1897 672,213 Holcomb Apr. 16, 1901 877,934 Lea Feb. 4, 1908 946,472 Stauier Jan. 11, 1910 984,995 Badge Feb. 21, 1911 1,043,502 Barker Nov. 1912 1,107,789 Hollandia Aug. is, 1914 `1,237,721 Stanley' Aug. 21, 1917 1,341,435 Olsen May 25, 1920 1,394,323 Matson Oct. 18, 1921 1,465,196 White Aug. 14, 1923 1,843,858 Z011 heb. 2, 1,932 2,292,094 Ti'lmas Aug. 4, 1942 2,334,135 Thurston Nov. 9, i943 2,377,905 `Sa'dcwsky .Ju-ne 12, 1945 2,398,121 Silvermaster Apr. 9, 1946 FOREIGN PATENTS Number l Country Date 603,359 Great .Britain June 15, v1948

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