US1401200A - Protractor for laying off lines, angles, and elevations in building and similar work - Google Patents

Description

A. R. SMITH.

PROTRACTOR FOR LAYING OFF LINES, ANGLES, AND ELEVATIONS IN BUILDING AND SIMILAR WORK'L APPLICATION FILED JAN. 20.1921.

1,401,200. Patented Dev. 27, 1921.

UNITED STATES PATENT QZ FEQE.

ARTHUR R. SMITH, OF NEW ALBANY, INDIANA.

PROTRACTOR FOR LAYING OFF LINES, ANGLES, AND ELEVATIONS IN BUILDING AND SIMILAR WORK.

'Specification of Letters Patent. Patented Dec. 2'7, 1921.

Application filed January 20, 1921. Serial No. 438,768.

To all w ham it may concern Be it known that I, ARTHUR B. SMITH, a citizen of the United States, and resident of New Albany, in the county of Floyd, State of Indiana, have invented certain new and useful Improvements in Protractors for Laying off Lines, Angles, and Elevations in Building and Similar Work, of which the following is a specification.

This invention resides in a simple, light, easily portable device for use by builders and contractors and others engaged in analogous work and who are not skilled engineers or,

provided with expensive scientific instruments in practically and eiiiciently laying off or determining the desired lines, angles and approximate elevations necessary .in their work. It is designed to save at least part of the time required. and trouble encountered heretofore in doing such work and t enable the work to be done more accurately as well as more rapidly. The novel features of the device will be understood from the following description and claims taken with the drawings. In the drawings:

Figure l is a perspective view of a device embodying my invention suspended on a line ready for use, the line being partly broken away for clearness;

Fig. 2 is a top plan view of the lower longitudinal arm or member of the device shown separately;

Fig. 3 is a cross section through the two arms and their pivot connection, the arms being in this instance one above the other and parallel;

Fig. at is a side view of a modified construction where the two arms shown parallel in full lines are made in sections and provided with hinges near their centers for folding into the position shown in dotted lines;

Fig. 5 is a similar view of another modification in which each arm is made of a tubular central portion in which the end porticns telescopically slide;

Fig. 6 is a detached side view of a portion of the longitudinal arm or member at one end showing thehooked support engaging the supporting line and the clamping screw to prevent end movement;

Fig. 7 is an end view of what is shown in Fig. 6;

Fig. 8 is a detached side view of a portion of the longitudinal arms at the opposite end from that illustrated in Fig. 6 showing the hooked support engaging the line:

Fig. 9 is a side view of what is shown in Fig. 8, and

Fig. 10 is a top plan view of the cross arm detached.

As will be seen by reference to Fig. 1 the particular embodiment of the invention thereshown includes an upper cross arm a made in the form of an elongated fiat strip of wood or other suitable material and a lower slightly longer longitudinal arm or member 6 also made in the form of an elongated flat strip of suitable material such as wood. These two arms are pivoted together so as to permit relative rotary turning to bring them into any desired angular relation and the lower arm has concentric with the pivot semicircular side extensions and the upper arm has a side notch or cutaway portion with a concentric circular inner surface. The pivot is preferably not midway of the length of the arms but in each case is somewhat nearer one end than the other as shown. To secure proper balance however the pivot is in the longitudinal center line of each and the material of the arms on opposite sides is so proportioned that the center of the pivot connection is approximately the center of gravity of'each arm. This may be accomplished by cutting away the sides of the arms the necessary amounts toward their ends as shown leaving the central parts fullwidth.

The cross arm a has secured to its under surface around the pivot a vernier which is in the form of a metal plate such as brass making contact on its lower surface with the top of. the lower arm 6 as shown in Fig. 2 and having a circular margin forming the visible bottom in the notch or cutaway portion of the upper arm a and projecting circularly therefrom. The lower longitudinal arm or member has secured to its upper surface concentric with the pivot and lying partly on the semicircular side extensions a circular plate having a circular inner margin surrounding the outer margin of the vernier and is in the form of a protractor with the necessary markings. It will of course be understood that the markings on the Vernier and protractor are such as to indicate the angular relations of the arms a and b. The pivot connection between the members consists of an interiorly screw threaded thimble m extending upwardly in a hole in the lower arm and provided with a lateral. flange at its lower end hearing on the lower surface of arm I) and an exterior-iv threaded thumb screw 6 entendingg downwardly through a hole in arm (a and engaging thethreads of thimble m and havinpjan upper enlarged head eX- tending; laterally over engaging the upper surface of the upper arm a. .lt-W1ll he noted tint this thumb connection permits easy cl Q grether .'n any adjusted position but when released permits freeturning. The thumb nut 6 preferably has a central hole or bore longitudinally thereof all the way through both arms whereby a pin or ten penny nail 1 may pass down through it With its point n bGlOW the device as shown in r 3 and that pin or nail may be driven ilto the top of a Wooden stake or other duel object support the device.

near its ends small and short similar upwardly projecting pins arranged in a central iosition laterally and inline with the of the pivot connection. These are "is the operator when the device is to the rig-ht position in use to lo- Eiccuratelv the angle indicated by ts or pins. The oWer arm 1 "us "for engaging a stretched wire, cord or similar element to support the apparatus. in the form shown these supports consist of all metal rods screwed into the upper face of arm 6 and havii their upper ends bent over into a transverse V shaped hook the inner points of the V beingin each case on the center line of the arm 5 and in line I mounted 1n or along; the top oi the upper with the center of the pivot connection between the arms. It w ll thus be observed that the inclined surfaces of the hooks Will cause them to slide automatically by the action of gravity on the it is at'the' porting 'tl vr're or cord until apeuand in the enact center supe arm (5 parallel to and with its in the same vertical plane as said This hook arrangement perand accurate application 03: the

wire but to prevent longia screw threaded clamplI passes upwardly through the at one end near one hook g and en- 'cs the under surface of Wire or. cord and forces up into greater frictional contact with the hook; it will he observed by comparing; Figs. 2 and 10 that the upper arm is enough shorter than arm 5 to permit it to turn to a position above and parallel arm 7) without striking the hooks l'nt'ae modified 'Eorm shown in Fig. 4: each arm formed. of two end sections hinged.

tion as illustrated in dotted lines and ani ine of thetivo members to- V r he upper cross arm chas on its surface 1 e along the arm a in the line together near the middle but at some distance from the pivot and it will be noted that the transverse pivot line of the hinge for the upper armc is along its upper margin permitting one end section to be turned upward on over to a horizontal position on andvsubstantially parallel to the other secthat the transverse pivot line for the hinge connection' of the lower sections constituting arm. '72 is along its lower margin permitting down turning of one section on the other and folding them as above indicated and as shown in dotted lines. Since'this folding may take placefwhen thearms a and'b are parallel one above thectherithe result is a very compact article of convenient shape and size for easy'transportation. The thickness of the parts and the arrangement of the hinges are such that" the projecting thumb screw 8 and pins do not interfere with the flat compact folding,

lnthc modification shown in 5 the central portions of arms aand Z) are tubular in form' and are pivoted together as above described as to the first form but it will be understood that the tubes are preferably formed of metal. I They'may be rectangular and flattened in cross section as shown or of an} cross sectional shape desired. In addition to the central pivoted tubular sections 7 is shown a level 0 arm or member a by Which the operator can determine certainly Whether that arm is in an exact horizontal position. diimlljv movable eight 79 may also be mounted in or on this arm to shift the center of gravity to bring; it into proper horiaontal position when the normal balance of the parts does not'do this. The presence of this level furthermore permits the user to determine when mounted on the ire or cord or even when supported in any other Way.

The mechanical structure and operation. or the device will be understood from the above description and therefore it is only necessary to describe the nature and manner of its use in practical Work and the advantageous functions and results secured by it. In laying off a building it is always easy to determine at least one building line and inusing my inventiona line or ire is stretched taut alongthat line in horizontal position and be ii longitudie roughly the inclination of the ground yond its ends secured to stakes or other fixed supports. The apparatus is then mounted on said line by means of hooks g and is moved longitudinally thereon until the center of the pivot connection is directly over the exact corner point or end of the known line. The thumb screw K is then tightened to prevent any longitudinal movement of the dev'ce on the taut line. The upper arm a in a horizontal position. is then turned on its pivot until. the vernier and protractor indicate the known angle of theside line leadin oil" from the line of the taut wire or cor l he thumb screw e of the pivot joint is then tightened to clamp the arms together at that angle to prevent turning. The side line is then easily run and determined by means of a cord or wire stretched on a line directly over the pins or sights f on the arm and the distance to the next corner is measured on that line. following this procedure for each side corner and line all of them can be quickly and accurately laid out. While the apparatus is especially adapted for use in building as above described. it is also adapted for many other uses where it is desired to determine an angle or fix a line on a known angle. Its uses are not limited to those cases where it hangs from a stretched line even in determining the horizontal position or angle of lines and it may be used in positions diiierent from horizontal to determine the pitch of roots, the angle of the corners of buildings or even the incline of the ground. It may be used in taking levels where great accuracy is not necessary by merely sighting along the projecting pins f in the preferred form the arms a and b are made of seasoned hard wood which when folded together make an article about 1" wide, 2- thick and five feet long and the vcrnicr has about 5} exposure. In this preferred form a ten penny nail. driven down through the central opening of thumb screw 0 into a stake or other fixed object will so and hold the device in fixed position with out the line support and the arm a may be turned to the desired angleand a wire or line connected to the uppe' projecting end of the nail and stretched oil at the proper un le to fix the desired line. lVhile I have described specific embodiments of my invention it will be understood that in its broar. .1 aspects it is not limited to the de tails of construction. Level 0 and weight 7) may be countersunk in arm (1.

Having; described. my invention what I as new and desire to secure by Let- 'er: Patent i l. in a device of the class described the ombination with an elongated member, of means thereon for supporting it from and below a stretched wire or cord in a definite position on a vertical plane therewith, a transverse member pivoted to said elongated member to turn horizontally thereon the portions extending on opposite sides being such as to balance each other, and circularly arranged scales carried by said members and concentric with the first point to indicate the angular relations of the members.

2. In a device of the class described the combination with an elongated member, of means thereof for supporting it from and below a stretched wire or cord in a definite fixed position on a vertical plane therewith a transverse member pivotedv to said elongated member to turn horizontally thereon, the portions extending on opposite sides being such asto balance each other, and circularly arranged scales carried by said members and concentric with the first point to in dicate the angular relations of the members and means for clamping said transverse member in adjusted position. I

3. In a device of the class described the combination with an elongated member, of means thereon for supporting it from and below a stretched wire or cord in a definite fixed position on a vertical plane therewith,

a transverse member pivoted to said elongated member to turn horizontally thereon, the portions extending on opposite sides being substantially balanced normally, a level on said transverse member, longitudinally movable means on said transverse member for so regulating the balance as to make said transverse member rest in a horizontal position, and scales carried by said members concentric with the pivot point to indicate the angular relations of the members.

4:. In a device of the class described, the combination with an elongated member, of means thereon for supporting it from and below a stretched wire or cord comprising upwardly extending hook members near its ends having contact surfaces inclined upwardly to sharp V-shaped points at the cen ter, an adjustable clamp cooperating with one of said hooked members to so engage the wire or cord as to prevent longitudinal movement, a cross member having upwardly projectingsights thereon near its ends and pivoted to said elongated member in the line of said sights and in the line of the sharp points of said hooks for rotary movement thereon in a horizontal plane and cooperating means on said elongated and cross members concentric with the pivot point to indicate the angular relations of the members.

5. In a device of the class described, the combination with an elongated member, of means thereon for supporting it from and below a stretched wire or cord comprising upwardly extending hook members near its ends having contact surfaces inclined upwardly to sharp V-shaped points at the center, an adjustable clamp coiiperating with one of said hooked members to so engage the

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