US2693642A

US2693642A - Line protractor

Info

Publication number: US2693642A
Authority: US
Publication date: 1954-11-09
Anticipated expiration: 1971-11-09

Description

1954 w. A. LACEFIELD 2,693,642

LINE PROTRACTOR Filed Oct. 24, 1951 Fig.

\ Wi/h'e A. L acefie/d I N V EN TOR.

Fig.

BY admwfim United States Patent 2,693,642 Patented Nov. 9, 1954 Free LINE PROTRACTOR Willie A. Lacefield, Hoquiam, Wash., assignor of onehalf to Mabel M. Lacefield, Hoquiam, Wash.

Application October 24, 1951, Serial No. 252,883

1 Claim. (Cl. 33-1) This invention relates to new and useful improvements in protractors and the primary object of the present invention is to provide a device for determining and laying out angles from a plumb line.

Another important object of the present invention is to provide a protractor including a supporting tube having means for engaging a line holding a plumb-bob, whereby angles may be readily determined by using the line as a vertical reference.

A further object of the present invention is to provide a line protractor that is extremely small and compact in structure to permit the same to be conveniently carried in the pocket of a user and which protractor may be quickly and readily attached to or removed from a line in a convenient manner.

A still further aim of the present invention is to provide a device of the aforementioned character that is simple and practical in construction, strong and reliable in use, efilcient and durable in operation, inexpensive to manufacture, and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, references being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is an elevational view of the invention in use;

Figure 2 is an enlarged elevational view of the invention removed from its supporting line; and,

Figure 3 is a view looking upwardly from the device shown in Figure 2.

Referring now to the drawings in detail, wherein for the purpose of illustration, there is disclosed a preferred embodiment of the present invention, the numeral represents a tubular support Whose ends carry transverse pins or

rivets

12 and 14 that extend through the

eye ends

16 and 18 of

hooks

20 and 22.

Notches

24 and 26 are provided in the ends of the support 10 and permit the

hooks

20 and 22 to pivot on the

pins

12 and 14 to a position perpendicular to the support 10.

Support 10 is provided with a central recess 28 in i which there is rotatably positioned a protractor plate 29 having circumferentially spaced graduations 30 in degrees of a circle. The zero and one hundred and eighty degree graduations are aligned with each other and are disposed longitudinally of the support 10.

A pivot 32 extends centrally through the plate 29 and the support 10 and is suitably held to the support. The outer threaded end of the pivot 32 extends outwardly through the center of an index arm 34 and receives washers 36 and a lock nut 38.

The pointed ends 40 of the arm 34 project radially outwardly from the plate 29 and the arm 34 is formed With a pair of longitudinally spaced

slots

42 and 44 in which pointed

lugs

46 and 48, integral with the arm, are positioned to selectively, register with the graduations 30.

In practical use of the present invention, in conjunction with a line L supporting a plumb-bob P, two loops L1 and L2 are formed in the line and receive the

books

20 and 22. The protractor plate may then be rotated to position the graduation directly over the 270 graduation. Then, the arm 34 may be rotated to determine or indicate a desired angle.

The protractor may also be used in a horizontal position. If there is a point oif the side of the line which must come in contact with the main line at a specific degree, the dial or plate 29 is set to that degree and the device is slid along the line until the sight line is in perfect contact with the object that is going to come in contact with the main line. This procedure can also be followed with the protractor in a vertical position, except the line supporting the protractor must be adjusted vertically.

Having described the invention, what is claimed as new is:

A line protractor comprising a tubular member having means at each end for engaging a line, said tubular member having a central recess in its outer periphery, a protractor plate secured to the member within the recess and having graduations in degrees on its outer face with a zero graduation and 180 graduation aligned with each other and with the longitudinal axis of the member, and a pointer pivoted to the center of the protractor plate, said line engaging means including a pair of hooks having eye ends, pivots extending through and securing said eye ends to the ends of the tubular member, the ends of said tubular member having notches therein accommodating said hooks and permitting said hooks to be pivoted to a position perpendicular to said tubular member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 3,147 Varney June 24, 1843 1,013,799 Meyer Jan. 2, 1912 1,401,200 Smith Dec. 27, 1921 FOREIGN PATENTS Number Country Date 26,386 Great Britain Nov. 12, 1897