US 2715778 A
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Aug. 23, 1955 K. A. MURDOCK ANGLE CALCULATOR 5 Sheets-Sheet 1 Filed April 26, 1954 v 3 KENNETH A. uunoocx INVENTOR Aug. 23, 1955 K. A. MURDOCK 2,715,773
ANGLE CALCULATOR Filed April 26, 1954 3 Sheets-Sheet 2 &\\\\\\ ,,,,,,;m m 58 32 mm 39 FIG-.4
" K T 5 ENNE H A lit 23 BY m g- 1955 K. A. MURDOCK 2,715,778
ANGLE CALCULATQR Filed April 26, 1954 3 Sheets-Sheet 3 KENNETH A. MURDOOK INVENTOR.
United States Patent ANGLE CALCULATOR Kenneth A. Murdock, Port Orchard, Wash.
Application April 26, 1954, Serial No. 425,522
8 Claims. (Cl. 33-97) This present device relates to the general art of mechanics calculating tools and more particularly to an angle calculator such as would be used by machinists to determine the taper of a piece of shafting for instance when the diameter at one terminal and the length of the tapered portion is given. This device consists of a platen which is spaced above a working surface by preferably three legs and which bears upon its face two scales which meet at right angles, each of which scales is provided with a Vernier index abutment which may be clamped in place and then a slidable and revolvable protractor arm adapted for engagement with each of the abutments. Means are provided so that the initial setting can be made with great exactness and the solution of the particular problem can also be read with exactness.
It is common in most useful work today to first lay out the work carefully on paper and for this purpose draftsmen are employed. Draftsmen, however, have their own way of laying out work and the tools of their profession being quite highly standardized, incline them to place dimensions on the drawings which, while serving their purposes to insure that the overall dimensions of the work will be exact, they quite often are such that they cannot be applied by the craftsman when he is called upon to construct a machine, for building or the like. It also follows that the average draftsman having so many dimensions to put on a single drawing normally does not feel it encumbent upon him to plot each one with exactness. This is aggravated further to a degree by the fact that he normally works on paper and the paper drawings or tracings are inclined to shrink or stretch and further usually the workman is provided with a print of those drawings. Therefore additional errors are brought into the drawings so that the scaling of them would lead to many inaccuracies. It therefore falls upon the workman to translate the drawings of the draftsman into the unit of measurement that he needs so that he can actually form the materials with the tools he has available for his use. In many instances he finds the need for a high degree of accuracy in his final calculations and it is an object of this invention to provide equipment which will enable the craftsman to attain the accurate dimensions desired, as he needs them. In distinction to the draftsman who has many dimensions to be concerned with, the average mechanic is usually interested in only one or two dimensions at a time during his production operation, therefore he has the time to determine these accurately if he had the means available. My present equipment is believed to adequately supply this need.
In the past many devices have been produced whose purpose is to take certain data and transform it into other desirable data. A large number of these devices have been examined but it does not appear that any of them fully serve the need for which this present tool is created. It is further necessary that this tool be reasonably compact and that it will be sturdy in order ice that its accuracy will not be impaired by the normal handling that a craftsman might give his tools.
The principal object of this present invention therefore is to provide an angle calculator which will take known data and calculate angles from it which will be of real value to the craftsman who is employed in the manufacturing or building fields.
A further object of this invention is to provide a calculating device on which two linear dimensions, taken at right angles to each other, can be very accurately set and then to provide a coacting protractor which can accurately engage the interstices thus set and convert the same into the desired angular measurement.
A further object of this invention is to provide a calculating device which further can be set to one lineal dimension and an angular value and which will make it possible to determine the second lineal dimension.
A further object of this invention is to provide a protractor head and an arm pivoted thereon, which assembly is capable of being movable as a unit so that the protractor arm can be brought into contact with the interstices of the two lineal scales.
A further object of this invention is to provide a calculating machine of such an embodiment that the various settings of the same can be set by the aid of verniers so that very accurate settings and readings therefrom can be made.
Furtheer objects, advantages and capabilities will be apparent from the description and disclosure in the drawings, or may be comprehended or are inherent in the device.
In the drawings:
Figure 1 is a perspective view illustrating the working surface of my calculating device with the same shown as set for the solving of a problem;
Figure 2 is a fragmentary plan view illustrating the lower right hand corner of the device of Figure 1 on an enlarged scale so that the interstices and the manner in which they are set will be more readily understood;
Figure 3 is a vertical cross sectional view taken along the axis of the abutment scale;
Figure 4 is a cross sectional view taken along the line 44 of Figure 2;
Figure 5 is a bracketed view taken along the broken line 5-5 of Figure 2;
Figure 6 is a perspective view showing a portion of the indices setting slider employed on the scale at the bottom of my device as illustrated in Figure 1;
Figure 7 is a cross sectional view taken along the axis of the protractor arm illustrated in Figure l and taken in a vertical sense through the axis of rotation thereof;
Figure 8 is a top plan view illustrating an attachment to be employed on the protractor arm of my device; and
Figure 9 is a vertical sectional view taken along the line 99 of Figure 8.
Referring more particularly to the disclosure in the drawings, the numeral 12 designates the platen or table which forms the main portion of my calculating device. This may be made of any suitable material. However to insure maximum accuracy it should be made of metal and preferably one which will not tarnish or rust. It is desirable that it be reasonably light and if the same is made of the heavier metals, then it could be lightened by piercing it with a plurality of lightening holes. In order to permit the easy handling of the Vernier adjusting means, it is desirable that the platen be raised from its supporting surface as by a plurality of legs 14.
Three legs are probably the preferred arrangement in that it insures a stable support for the platen. Upon the upper surface of platen 12, and preferably recessed 17 respectively.
into the same in order that their tops will be on the plane of the top of the platen, are the two intersecting scales 16 and 17. These scales for the purpose of this equipment 12 to the .end that the vernier indices will have a full range of adjustment.
Disposed for movement longitudinally of scales 16 and 17 are the abutment members 20 and 22. Each abutas 24 and 26. These members are both formed after A the showing of Figure 4 wherein the anchoris provided with a bifurcation as 28 so that one of the legs as 29 will lie on top of the platen and the other leg 30 beneath the platen. This "arrangement generally positions the anchor on the platen and it is prevented from comingofi the'edge of the same by an upwardly disposed detent 32 adapted to rest in the grooves 31 and 33 which grooves are disposed in parallel relationship with scales 16 and Detents 32 are formed as part of companion screws 35 which are similarly constructed and provided preferably with knurled nuts 34. The upper legs 29 of the anchors are transversely slotted at 36 to receive the adjusting or positioning cylinder nuts 37. These nuts which are preferably longitudinally grooved,
abut in' working relationship, each end of slots 36 and are disposed upon the threaded studs 39 and 40. These studs are-in turn anchored fixedly to abutment members 20 and 22. The metal is preferably milled away from the sides of the slots 36 as indicated at 41 so that the finger of the user can easily revolve nuts .37. a
. Abutment members 20 and 22 are bifurcated in the same manner as the vernier members and are similarly provided with locking screws 35 which terminate in the knurled nuts or heads 44.
Abutment 22 is relieved and slotted to provide the vernier 46 which is cooperativelydisposed with respect to scale 17. It' is also provided with 'a pointed abutment index member 47.
Abutment member 20 has many of the characteristics of abutment 22 and is further provided, in addition to the vernier 50 which operatively engages scale 16, with a second vernier 52, which is disposed for coaction with an adjustable indexabutment scale 54 which is pointed at its upper end to provide an adjustable abutment. Scale 54 is guided by an overlapping portion of vernier 52 which holds the scale in a recess 55 formed in abutment 20 and further has a clamp member 57 which is provided with a locking screw 58 by which the adjustable abutment can be fixedly secured to abutment 20; r p
'The abutment scale 54 is adjusted by means of the vernier anchor 61 illustrated in Figure 1, and in'section in Figure 3. Adjustment of the scale 54 is obtained by releasing clamping screw 58 of the clamp member and clamping the same by tightening screw 60. Adjustment has been effected by turning the knurled nut 62 which threadedly engages stud 63 which in turn is secured to abutment 20. A portion of nuts 62 as 64 is disposed'within the bifurcated portion of member 61 and thus is capable of moving the'abutment scale 54 in either direction in order to obtain the desired setting on vernier 52.
Slidably disposed across the base or platen 12 and above scale 16 is the protractor base 70. This protractor base is limited in movement by overhanging flanges 71 and 72.
Pivotably secured to protractor base is the protractor index and arm assembly generally designated as 74. The method of achieving this pivoted action is'illustrated in Figures 7 and 8 in which a boss 75 is formed either as part of, or secured to, the base 70 and has extending upward fromit the clamping screw 76 which is in turn provided with a clamping nut preferably knurled as at scales, a protractor base positioned on said plate in the V 77, a compression spring 78 is acted upon by nut 77 thus placing frictional pressure upon discs 79 seating it upon the margins of hole 87 formed in base member 80, and thus serving to provide a tightening arrangement for the protractor assembly 74. Boss 70 extends upwardly into an opening in member 80 and centers the same. The protractor vernier of the assembly is adjustably secured to the protractor arm by being formed as part of base member-80 which is accurately machined to mate with a similar machine surface on the underside of arm 83. This provides a centering abutment at 81. Adjustment is secured by having arcuate slots 84in member 83 for each of screws 82.- This arrangement permits the accurate adjustment of vernier 86 with respect to the working or lower edge of arm 83. It has been found desirable to provide a mounted reading glass as 88 so that vernier 86 can be read very accurately.
Vernier 86 is positioned in operative relationship with the protractor graduations 89 which are preferably engraved or engine cut on base 70.
In Figure 8 is illustrated a'removable bar 90 which is adapted to be clamped on to arm 83 of the protractor assembly. The clamping means is illustrated in Figure 9 in which a transverse groove is provided at 92 to receive arm '83 and a clamp member 93 is arranged to press down on arm 83 under urgence of nut 94. This member is employed when it is desired to lay off or determine the angle of a piece of material as the rafter end R. In this case the upper edge 15 of platen 12, which is parallel to the lower edge and scale 16, is abutted against one margin of the rafter and the rafter cut is then determined by scribing a line on the inner surface 95 of arm 83 and the inner surface 96 of bar 90.- This is merely an illustrative use of this equipment and a skilled craftsman will 7 be able to apply this mechanism to many of his needs.
To illustrate the use of this device as it will be most commonly employed, it may be assumed that a tapered shaft is beingprepared for a marine propeller hub. The diameter of the large end of the bore is set on scale 17, employing vernier 46 and its associated parts. This positions index 47; The axial length of the bore is set on scale 16 by means of vernier 50 and its associated parts, the right band edge of scale 54 is in alignment with this index. The next step is to set scale 54 so that vernier.
52 will read the small diameter of the bore.' This positions the pointed abutment end of scale 54. Base 70 an angle. calculator.
Having thus disclosed, the invention, I claim:
1. An angle calculator, comprising: a plate having a pair of graduated scales intersecting at right angles and positioned near two adjoiningedges of the plate, apair of traveling abutment members mounted on said plate and means guiding said abutment members in movement along said scales and means for securing the abutment members in various adjusted positions relative to said included angle between .said scales and said plate having guideways supporting the protractor base in movement toward and away from one of said scales, said protractor 1 base having an arm mounted to pivot about a point thereon and having a scale in degrees adapted to show change a in the angular position in degrees of said'arm relative to said protractor base as it pivots about said point, and said abutment members having indicator abutments positioned v to be contacted by said arm. a
2. The subject matter of claim 1 in which a first of said abutment members has a third scale 'slidably' mounted thereon to move at right angles to the graduated scale associated with said first abutment member, said third scale forming the indicator abutment for said first abutment member adapted to be contacted by said arm.
3. The subject matter of claim 2 in which there is a vernier scale on each abutment member disposed to read on the associated graduated scale, in which there is a vernier scale on said first abutment member disposed to read on said third scale, and in which there is a reading glass positioned for viewing the protractor degree scale.
4. An angle calculator, comprising: a plate having a pair of graduated scales directed at right angles to each other and positioned near two edges of the plate, a pair of traveling abutment members mounted on said plate and means guiding said abutment members in movement along said scales, a protractor base positioned on said plate in the included angle between said scales and said plate having guideways supporting the protractor base in movement relative to said scales, said protractor base having an arm mounted to pivot about a point thereon and having a scale in degrees adapted to show change in V the angular position in degrees of said arm relative to said protractor base as it pivots about said point, and said abutment members having indicator abutments positioned to be contacted by said arm.
5. An angle calculator, comprising: a plate.having a pair of graduated scales directed at right angles to each other, a pair of traveling members mounted on said plate and means guiding said traveling members in movement along said scales and manually operable means for securing the traveling members in various adjusted positions relative to said scales, a protractor base positioned on said plate and said plate having guideways supporting the protractor base in movement relative to said scales, said protractor base having an arm mounted to pivot about a point thereon to register with said traveling members and having a scale in degrees adapted to show change in the angular position in degrees of said arm relative to said protractor base as it pivots about said point, and
manually operable means for securing the arm in various adjusted positions relative to said protractor base.
6. The subject matter of claim 5 in which each traveling member is positioned at an edge of said plate and is bifurcated with a lower arm portion positioned below said plate and an upper arm portion positioned above said plate, said plate having a groove in its under surface extending along the path of travel of each traveling member, and said manually operable securing means for each traveling member includes a movable threaded locking member mounted in the traveling member having an inner detent end positioned in the corresponding groove in said plate and nut means on the other end of the locking member operable to tighten the threaded locking member to press said detent end in said groove locking the traveling member in position.
7. An angle calculator, comprising: a plate having a pair of graduated scales directed at right angles to each other, a pair of traveling members mounted on said plate and means guiding said traveling members in movement along said scales, a protractor base positioned on said plate and said plate having guideways supporting the protractor base in movement relative to said scales, said protractor base having an arm mounted to pivot about a point thereon and having a scale in degrees adapted to show change in the angular position of said arm in terms of degrees, said arm being disposed to be moved into registry with said traveling members.
8. The subject matter of claim 7 in which each traveling member has a Vernier scale positioned to be read on the associated graduated scale and in which there is associated with said degree scale a Vernier degree scale.
References Cited in the file of this patent UNITED STATES PATENTS 71,595 Evans Dec. 3, 1867 1,969,296 Arizpe Aug. 7, 1934 2,082,008 Kauffman -L June 1, 1937 2,461,795 Williamson Feb. 15, 1949