US 2575245 A
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Description (OCR text may contain errors)
NOV. 13, 1951 E. w. CARLSON Erm.
ENGINEERS POINT FINDER Filed June 16, 1948 jjj Patented Nov. 13, 1951 UNITED srA'rss rsNT OFFICE ENGINEERS POINT FINDER Evert W. Carlson and Vernon J. Flink, Cambridge, Minn.
2 Claims. l
This invention relates to a point locator for use in general surveying and building operations.
It is an object of the invention to provide a support for a plumb line which can be conveniently and accurately located over a point which may be fixed by a transit or by means of which a previously fixed point can be readily lined up with the use of a transit or some other meas-- uring instrument.
Another object of the invention is to provide a plumb line support with means for raising and lowering,r the line and holding it in various vertically adjusted positions.
Another object of the invention is to provide a plumb line support including a generally horizontally shiftable guide which is movable relative to the remainder of the support so that the plumb line can be shifted in a horizontal plane.
Still another object of the invention is to provide a readily collapsible and readily set up plumb line support in addition to means for assisting in maintaining the plumb line in a vertical position and checking its swing, said latter means also serving as a finder by means of which the plumb line can be more readily and accurately located from a distance.
The above and other objects and advantages of the invention will more `fully appear from the following description made in connection with the accompanying drawing, wherein like reference characters refer to the same parts throughout the views, and, in which:
Figure 1 is a side elevational view of the apparatus; u
Figure 2 is a plan view thereof;
Figure 3 is an enlarged fragmentary view partially in vertical section of the upper portion of the structure; and
Figure 4 is a section taken approximately on the line 4 4 of Figure l.
The vertical stand or tripod includes an annular casting 5 which is supported by three legs 6 which are pointed at their lower ends so that they can be rmly set in any desired location. The upper ends of the legs 6 lie between pairs of lugs 1 which extend downwardly from the annular table member 5 and are pivotally connected to the legs by means of bolts having swing nuts 9 thereon. As a result the legs 6 can be individually placed at different angles.
The annular table 5 has a central aperture I0 shown in Figure 3. Beneath the stationary table portion 5 is an inverted cup-shaped member II having an upstanding central threaded post I2 upon which is screwed a disc I3. superimposed upon the disc I3 and welded thereto is a strengthening plate I3a. A shoulder I4 on the post I2 prevents the disc I3 from being turned down far enough to cl-amp the stationary table portion 5 between the disc I3 and the cup II. Preferably when the disc I3 is tight on the threaded post I2 it is a close yet freely sliding nt between the stationary annular table portion 5 and the spaced cup and disc. Set screws I5 are threaded through the disc I3 and plate I3a and are adapted to bear against the stationary table portion 5 to lock the -movable table portionmadeup of the cup and disc against shifting movement. WhenY the set screws I5 are loosened, however, the movable table portion can be shifted in a horizontal plane.
The inverted cup II hasiaring IIsupported therein by means of pointed set screwsv I1 placed at two opposite points on the side wall of the cup I I. This permits the ring I6 to tilt about the common axis of the screws I1.
Located concentrically within the ring I6 is an upright cup-shaped casting I8 which is pivotally supported between opposite points on the ring I6 by means of set screws I9 having their common Iaxis placed at right angles to the set screws I'I. This supports the cup I8 for substantially universal pivotal movement relative to the remainder of the structure. Mounted on the disc I 3 is a bracket 20 whose upper portion is composed of spaced fork arms 20a between which is mounted a reel 2I on a shaft 22. The shaft 22 is provided with a small hand crank 23. One of the fork arms 20a has a thumb screw 24 threaded therethrough and adapted to engage a side of the reel 2l so that it can be releasably secured against rotation.
The upstanding post I2 on the inverted cup II is provided with a longitudinal vertical aperture 25 which extends down through a lower post element 26 inside the cup II. The post 26 terminates in the inner cup I8 at a point approximately at the same elevel as and at the intersection of the axes of the screws I1 and I9.
Extending downwardly from the cup I8 is a tube 21 whose lower end is provided with an apertured plug 28. As shown in Figure 1, the tube 21 is provided with alternating contrasting colors as at 29 and 30. A plumb line 3| is shown wound upon the reel 2I and extending downwardly through the posts I2 and 26, the tube 21 and through the apertured plug 28 in the bottom of said tube. A plumb bob 32 is secured to the end of the plumb line 3 I.
The plumb line can be raised or lowered by means of the reel 2l with its handle 23 and locked in any suitable vertical position by means of the thumb screw 24 on the reel assembly.
When the device is set up above a previously located point the tripod or stand is placed approximately over the point and leveled by proper manipulation of the independently movable legs 6. The movable table portion comprising the disc I3 and inverted cup il along with the structure supportedthereby is shifted horizontally'on the stationary annular table ring 5 until the plumb bob 32 is located over the point as indicated in Figure 1. The thumb screws l5 canv then be tightened to hold the plumb linedirectly over the desired point as long as needed.
The tube 21 through whichl the' plumb-line extends is relatively long and serves to quickly stop swinging movement of theplumb linef and.
also prevents it from being swung by the wind.
Ihe depending post 26 in the cup H terminatesv at the point of intersection at the axis of the screws? |21r and IIS-so that', evenif thetfube-ZT is'at an angle to the horizontal table elements, the plu-mb'- line will be held inf the center oitthe-tnbe andi will hang inta proper verticali position.
If desired,the stationary annular table' portion 5 can' befprovided: with aisxriall upright. flag standard' 3`3 upon which a; Warning flag 34 be mounted so that the: device` can be readily seen when" placed. in locations such as on streets and highways and will not be damaged Vby, tra-flic.
It will, of course, be' understood that various changes'may be made inthe' form, details, arrangement and proportions ofthe various parts Withouwt departingrfrom the. scope of: ourY invention;A f' jr! What: we claim is:
L. In an' engineers" point locator, an upright stand having a-table at it'stop, aportiony of said 4 table being substantially horizontally shiftable, a plumb line guide carried by said shiftable table portion, and a plumb line takeup device mounted on said table separate from said plumb line guide but cao-operating therewith and shiftable with f said table and with said guide.
2. In an engineers point locator, an upright stand having a table at its top, a portion of said table being substantially horizontally shiftable, a plumb line guide carried bysaid shiftable table portion, said plumb line guide having an aperture extending throughout its entire length to accommod-ate a plumb line therein, a reel on said shiftable table (zo-operating with said plumb line guideand'upon which a plumb line is adapted to be wound, and said reel having releasable locking: means thereon to hold said plumb line in various extended positions.
EVERT W. CARLSON. VERNON J. FLINK.
REFERENt-JESA CITEDv The following references are of record? in the fil'e of this patent:
UNITED STATES' PATENTS Number Name Dat-e 839,005 Lafon Dec. 18, 1906 1,010,339 Angel Nov. 28, 11911 1,943,295A Burns Nov. 5, 1912 2184,505 Danley Dec.' 26, 1939 22459901 Chaskin. June 17 1941 FOREIGN PATENTS Number. Countryv Date 58,785: Germany. Sept.. 18, 1891 325,920 Italy Apr. 17, 1935