US2669027A - Micrometer tangent bar - Google Patents

Description

Feb. 16, 1954 c. R. WILSON MICROMETER TANGENT BAR Filed July 12, 1950 2 Sheets-Sheet 1 Fig./

\ Fig.2

Charles R. wllson INVENTOR.

1954 c. R. WILSON MICROMETER TANGENT BAR 2 Sheets-Sheet 2 Filed July 12, 1950 Charles R. Wilson INVENTOR.

and

Wm WMZM Patented Feb. 16, 1954 UNITED STATES PATENT OFFICE MICROMETER TANGENT BAR Charles R. Wilson, Pekin, Ill.

Application July 12, 1950, Serial No. 173,262

Claims.

The present invention relates to improvements in angle measuring devices, and more particularly to the type of angle measuring device adapted to be set at predetermined micrometer angles.

An object of the present invention is to provide a tool for measuring angles or setting angles for use in die making operations and the like.

A further object of the present invention is to provide an improvement over existing angle setting tools, the present invention being based on the fact that angles may more accurately be measured by their tangent values than by their sine or cosine values.

Still another object of the present. invention is to provide an improved angle setting device which may be employed in conjunction with specially prepared tables for micrometer settings whereby preselected angles may be set.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawings merely show and the following description merely describes embodiments of the present invention, which are given by way of illustration or example only.

The best form in which I have contemplated applying my invention is illustrated in the accompanying drawings, wherein:

,taken substantially along the plane of line 5 5 01 Figure 4; v Figure 6 is a vertical transverse sectional viei taken substantially along the plane of line 66 of Figure 5; and

Figure 7 is a vertical transverse sectional view taken substantially along the plane of line 1-1 0! Figure 5.

. Referring more particularly to the drawings, 2.

wherein like numerals designate like parts throughout, numeral l0 designates generally the angle plate, numeral l2-designates generally the base supporting means,-numeral I 4 designates generally the screw actuating means and nu-'- 2 meral l6 designates generally the micrometer nut means.

The angle plate It is of substantially triangular cross section being provided with a pair of downwardly extending ears l8 and 20 which are apertured at 22. The lower face 24 of the angle plate l0 forms a predetermined angle with respect to the upper face 26 and is provided with a dovetail slot 28 throughout its length. The base 32 of the angle plate I0 is provided with a recess 34 in which is disposed an end plate 36. The end plate 36 is secured to the wall of the recess 34 by means of a plurality of Allen head screws 38.

The base supporting means I 2 is of substantially rectangular form and is provided with a pair of upstanding bearing portions 40 and 42 which are adapted to embrace the ears l8 and 20 and rotatably support the bearing pin 44. The bearing pin 44 is adapted to extend through each of the ears l8 and 20 for pivotally supporting the angle plate [0.

As seen best in Figure 5, the end of the base supporting means I2 opposite to the pivot pin 44 is provided with a bearing mounting housing 46 which is formed with a pair of dowel holes 48 and 50 and a plurality of bores 52. The end face 54 of the base supporting means I2 is provided with longitudinally extending dowel pins 56 which are adapted to be received Within the holes 48 and 50 of the bearing housing 46 for positioning thereby. The housing 46 is secured to the base supporting means I2 by means of a plurality of Allen head screws 58.

The bearing housing 46 is provided with a centralboretll, a counterbore 62 and a threaded portion 64. The outer race of the conventional ball bearing unit 66 is press fitted into the counterbore 62 and is rigidly held in position by means of the locking ring 68 which is threadably engaged with the threads 64.

The base supporting means i2 is also provided with a dovetail slot 10, as best seen in Figure 6.

The screw actuating means !4 is rotatably supported by its bearing portion 12 within the con:- ventional bearing 66. A handle supporting element 14 is provided with a counterbore 16 in which is received the end of the bearing portion 12. The set screw 18 secures the elements .114 from rotation with respect to the portion 12, and a screw is threadably engaged-in a bore 82 in the end of the bearing portion 12 with its head engaging the outer surface of the elements 14 for retention thereby. The handle 84 of any 3 desired form is threadably mounted in the elements 14 and 86.

The nut micrometer means It includes a screw engaging portion 88 provided with an internally threaded bore 911 and is split at 92. The nut portion 88 is provided with a threaded bore at 94 in which is threadably received the end of a screw 96. The head portion of the screw 96 abuts the side of the nut portion 88 on the opposite side of the split 92 and has the threaded shank portion freely received in a bore 98. With this arrangement, it will readily be seen that the degree of friction between the screw means [4 and the micrometer nut means l6 may be varied.

The lower end of the micrometer nut means It is provided with a V-slot Hi6 which provideslcoma munication between the threaded bore all and, the bottom face of the nut 1'6. Positioned within the V-slot its is a dovetail slot engaging element 1632 which is provided with threads 1534 for eng-agenient with the screw means M. A pair of screws )5 are adapted to maintain the member L111; in position and to vary the degree of friction between the member and the screw means It, and also between the member i-iiii and the dovetail slot iii, The nut it is provided with a pair of ears and lit which are apertured for receiving the pivot pin iii upon which the slide element lid is pivotally mounted.

The slide element 3 i4 is provi with a dovetailed head lit? for sliding en, sent "with the dovetail slot 28..

As seen in Figure l, the base supporting means l2 may be provided with indicia markings [18 on its upper surface which may be employed to determ ne t e p i of he. mi rome u it with respect to the pivot pin 4.6.. Further, the element "at is; provided withexternally inscribed n ic a i3 which be calibr ted u in determining the angleof the upper facett of the angle plate ill.

The foregoing description, taken in conjunction with the drawings is believed to set forth the operation of the device which. will be readily apparent to one skilled in the art. rotating the handle M, the screw means It will be simultaneously rotated within the; bearing means 56, and will cause the micrometer; nut to be threadably moved longitudinally: of the base 1-2 with the slide member H 4 engaged in the dovetail sl t 23. T e mo ement 9f. e it n the Ht will causev pivoting movement of the angle plate iii.

It will be noted that the underside of the, plate H2 at 24 forms a predetermined angle with respect to the horizontal. and angle is termed the. base angle. The distance :11, on Figure- 2, is of, a fixed amount and is employed for determining the actual angle of the upper surface 26 with r spe t. to. t z taL. Thus, f. it s des r that the base 26 be'positioned at a predetermined angle theta, the angle theta is added to the base angle, and the cotangent of the result angle is evaluated. The product of the cotangent of that angle and the amount :1: gives a result in inches which is the base of a triangle. The micrometer screw may then be rotated until the indicia H8 and 120 each give the reading of the aboveresult. It is believed that one skilled in the art will readily understand how angles of greater than 90 may be set.

Inasmuch as the present invention involves the use of tangents and cotangents rather than due an cc in s it wil .v be. s en hat e: e ree of accuracy pos ible wi h" this device is high.

By merely This will become obvious when it is realized that the tangent and cotangent tables read to a greater number of significant numbers than the sine and cosine tables.

If desired, special tables may be made for use with various sizes of the tangent angle bar and for setting the dial at predetermined degrees, minutes, or seconds based on the above formulae. ihe use of the tables would eliminate much of the time consumed in figuring out the above formulae.

Some changes may be made in the construction and arrangement of the parts of my device withoutdeparting from the real spirit and purpose of my invention, and it is my intention to cover by l-IIY'CIMHISELIIY modified forms of structure or use of, mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

Having thus described my invention, what I claim to be net-v is:

3,. A tangent bar comprising a supporting base, a pivotable means pivotally mounted on said-supporting base, an actuating screw rotatably imied on said supporting base and being secured against longitudinal movement thereon, means reciprocally engageable with said actuating screw and said pivotable means and being actuated by said actuating screw to effect pivoting of said pivotable means, said pivotable'means including a plate having an upper and a lower face angularly disposed relative to said upper face, a longitudinally extending dovetailed slot in the lower face of said reciprocally changeable mean compr a micrometer nut reciprocably moved y said a uat ng s r wm gl a slide el men iv t.- aily connected to said not and slidably engaged in the slot of said plate whereby longitudinal movement of said nut will effect sliding engagement between said slide element and said plate. whereby said plate will be pivoted, said supporting base including a longitudinally extending dovetailed slot, the lower end of said nut having a V-shaped slot therein, a dovetail slot engaging element disposed in said V-shaped slot. and means on said nut adjustably maintaining said slot engaging element within. said base slot whereby the friction between the element and the base slot may be varied. v

2. An angle measuring device consisting of an elongated base having first and second ends, a t n a d pivo o. a d fir e d, a o e a n nut mounted on said base for sliding movement between the ends thereof, a slide pivotally mountedon said nut and Slidably secured to said standard, an actuating screw rotatably journaled at said second end of said base and threadedly received in said operating nut whereby rotation of the screw will pivot the standard about the base, said standard having topand bottom faces, the topface beingz flat and the bottom face. being inclined thereto With th v pivot being located at the end of the standard away from the apex of the angle, the bottom face of said standardforming an inclined trackway thereon, said. slide being slidably and non-rotatably secured in: said track-.- way.

3. An angle measuring device compris n of an elongated base having first and second ends, a standard pivoted to said first nd an o rati nut, guide means on said base mounting said operating nut for sliding movement between the ends thereof, a slide, pivotally'rnounted on "d nut m ans idablv se u ing ai slide t sta dard, an act ating s r w roi ablv inc-. 1 else on said second end of said base and threadedly reeived in said operating nut whereby rotation of the screw will pivot the standard about the base, said slidably securing means including said standard having top and bottom faces, the top face being fiat and the bottom face being inclined thereto with the pivot being located at the end of the standard remote from the apex of the angle, said bottom face having a trackway formed thereon, said slide being secured in said trackway.

4. An angle measuring device consisting of an elongated base having first and second ends, a standard pivoted to said first end, an operating nut, guide means on said base mounting said opcrating nut for sliding movement between the ends thereof, a slide pivotally mounted on said nut, means slidably securing said slide to said standard, an actuating screw rotatably journaled on said second end of said base and threadedly received in said operating nut whereby rotation of the screw will pivot the standard about the base, said slidably securing means including said slide having a dovetail projection thereon, said standard having top and bottom faces, the top face being fiat and the bottom face being inclined thereto with the pivot being located at the end of the standard remote from the apex of the angle, said bottom face having a dovetailed groove formed therein, said projection seating in said groove.

5. An angle measuring device comprising of an elongated base having first and second ends, a standard pivoted to said first end, an operating nut, guide means on said base mounting said operating nut for sliding movement between the ends thereof, a slide pivotally mounted on said nut, means slidably securing said slide to said standard, an actuating screw rotatably journaled on said second end of said base and threadedly received in said operating nut whereby rotation of the screw will pivot the standard about the base, said slidably securing means including said standard top and bottom faces, the top face being flat and the bottom face being inclined thereto with the pivot located at the end of the standard remote from the apex of the angle, said bottom face having a trackway formed thereon, said slide being secured in said trackway, said guide means including said base having a dove-tail groove therein, said nut being slidably disposed in said groove.

CHARLES R. WILSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,048,124 Asworth Dec. 24, 1912 1,521,341 Thacher Dec. 20, 1924 1,658,736 Ortmeier Feb. 7, 1928 1,683,509 Wescott Sept. 4, 1928 2,056,948 Bensen Oct. 13, 1936 2,113,287 Baldenhofer Apr. 5, 1938 2,297,105 Laukhuif Sept. 29, 1942 2,353,886 Findley' July 18, 1944 2,385,309 Spencer Sept. 18, 1945 2,435,693 Orlow Feb. 10, 1948 2,465,445 Harris Mar. 29, 1949 2,578,261 Orr Dec. 11, 1951 FOREIGN PATENTS Number Country Date 605,242 Great Britain July 19, 1948

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