US 909529 A
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Patented .Ta.n.-12, 1909.
[fil/2 [01? I A. BLAIR.
LBVELING INSTRUMENT. APPLICATION FILED FEB. 10, 1908. 909,529.
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ALEXANDER BLAIR, OF ORILLIA, ONTARIO, CANADA.
Specification of Letters Patent.
Patented Jan. 12, 1909.
Application filed February 10, 1908. Serial No. 415,132.
To all 'whom it may concern:
Be it known that I, ALEXANDER BLAIR, a subject of the King of Great Britain, resident of the town of Orillia, in the county of Simcoe, in the Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Leveling Instruments, of which the following is a speciication.
My invention relates to improvements in levels and the object of the invention is to devise a level which will eliminate the use of straight edges and stakes in building operations and whereby the level obtained is much more reliable as compared with the level sought, and it consists essentially of a tubular casing for containing spirits flexibly connected, and means for emitting` the air from said tubular bodies during the operation of taking the level, as described in detail in the present specication and shown in the accompanying drawings that form part of the same.
In the drawings Figure l is a perspective view of the tubular instruments and flexible connection. Fig. 2 is a vertical section of the instrument.
Referring to the drawings, l is the outer casing having the lugs 2 extending from the side thereof and a handle 3 fxedly secured to said lugs for carrying the casing from place to place.
t is an opening through the lower end of the casing 1 having a threaded inner wall for the insertion of the nipple 5 secured to the exible tube 6. The casing 1 is open at the top and has the vertical slots 7 through the wall thereof diametrically opposite one to the other.
8 is a glass tube inserted in the casing 1 and resting on the bottom of said casing surrounding the opening 4.
9 is an air nozzle rigidly secured on the top open end of the casing 1 having the stop cock 10 in the central portion 11 thereof. The stop cock 10 may be omitted if desired.
12 is the upper end of the nozzle portion 9 having the central passage 13 extending downwardly from the upper end thereof into the chamber 14. The surface surrounding the lower entrance to said opening 13 forms a valve seat.
15 is a valve having its stem 16 extending upwardly through the passage 13 and beyond the upper end of the portion 12 terminating in the button 17 for pushing the said valve from its seat.
18 and 19 are passages through the central and lower parts of the nozzle 9 forming a 'continuation of the passage 13 into the tube 8 and interrupted by the said stop cock 10 forming the means of communication when turned to the open position. The stop cock is for the purpose of completely closing the passage through to the upper end of the f nozzle during the transportation of the instrument and thus preventing any possibility of the emptying of the liquid through the upper end of the said instrument.
20 is a cushion helical spring inserted in the chamber 14 beneath the valve 15 and exerting a continuous upward pressure on said valve and keeping said valve yto its seat.
21 are air passages through the walls of the portion 12 of the nozzle 9 and communieating with the central passage 13 above the Valve seat and allowing the free egress of air from said passage on the release of the valve 15.
In the use of this apparatus,- a nipple is connected to the other end of the flexible tube and attached to a similar instrument and the instruments and tube lled to the desired level with spirits by removing one of the nozzles.
The level of the spirits in the instruments is marked by a suitable pointer formed of the band 22 encircling the casing 1. The band is in the form of a clamp with a small thumb screw 23 for tightening it to any desired position.
One instrument is held at a certain part of the building bringing the level of the spirits in that instrument to the top of the Wall or other point, then the other instrument, at the other end of the flexible tube, is taken to any other part of the building and the spirits immediately find their own level in the said second instrument which will indicate the level which the wall is to be raised or lowered to at that point, the pointer on the casing to be used for marking purposes.
In order that the builder may find the proper level the button 17 is pressed until any undue pressure of air in the glass tube 8 above the liquid is relieved thus obtaining an exact level. This means of obtaining the levels, that is, the release of the air pressure at the proper time is the only success- Y ful method of using this particular type of* leveling instrument as the air collects with in the casing of the instrument and exerts quite a pressure on the liquid and it is only by exhausting any undue pressure in both Y instruments that a perfect level can be found.
That IV claim as my invention is 1. In a leveling instrument, a casing having a suitable 4opening at the lower end and an open top end, an air nozzle rigidly secured to the upper end thereof having an air passage therethrough and a chamber intermediate of the length of said passage, Va
valve spring-held to its seat at the lower sage through the lower portion to said een-l tral portion and from said central portion to a chamber immediately thereabove and from said chamber to the top of the nozzle, a stop cock having a passage therethrough f adapted torconnect the Vaforesaid passages through the central portion to said chamber,
and an air valve having its stein extending upwardly beyond the top of the nozzle and a button on the end of said stem, said valve being spring held to a seat formed on the top Wall of said Chamber, substantially as de-r scribed.
Signed at the city ofToronto, in the county of York, Province of Ontario, in thek Dominion of Canada, this third day of January, 1908. 1
kALEXANDER BL AIR.
lVitnesses H. DENNisoN, Y E. WiLKIN.