US2521745A - Apparatus and method for locating pipes - Google Patents

Description

Sept. 12, 1950 c. E. POPE APPARATUS AND METHOD FOR LOCATING PIPES Filed June 27, 1949 CLAUDE E. POPE INVENTOR.

ATTORNEY vgkv N. k\ L \-A\- w\ 7. -mvm mm mm N 0 h. 3 8 cm 8 0m mm m mm no mu mv m mm M mm hm wm mm #m m mm ON Om vm Mm a :It is another ob ect =04f-myjnvention to enable in ate meas re the a e' l na wpipe from a-pointwhere itlis exposed to a point-Where the ,pipeis hidden-fromview. ,1

2 Other objects of my invention willibe evident from a considerationof: theiollowing specification and accompanying! drawing; in which 1. l

,Eig 1 .isa sectional elevation of an underground 1 pipe ,with the apparatus 1 of thisiinvention. shown as employediniuse.ofvthe invention;

'thezlength of my; r 1 1; often im'portant in electrical wiring'and Patented Sept. 12, 1950 cs-mixer P US:ANnMETHonFonfjnoATIN a o V PIPES My r 1., i

I muta ng? ba i m' Gillie Appl cation June 27, misisiaa 101,69

This invention lsior locatingiand mapping the Me -1, p

from'a point outside the pipe. wt

lt is one of the principal objects of my; tidn tq provide a pipe locating method-which sir s-t e qa cn i i ip a c at l Fig. 21s a ,view,elargely in 'section,*"of the exi-ploring head muchsenlargedrfrom-that shown in Fig. 1; and l i Fig. 3 is a partial sectionatplane- 3'-3 of Fig.

2,, and inpart a I diagram illustrating certain .functions;andstepsiirthe use of'the-apparatus. 30

'ioutlet il 2 is unknown 'both as to *direction from 'ioutlet t2 in a horizontal 'planegandas to dept below the surface-oi the ground at z'rg'that isg-the vertical: :dista'noe'my corresponding to the direction of gravitational force; is unknown. Y The two problems arez' 1(1) to determine where y is such 6:0 =that a3 isdirectly below y and (2) todetermine cable running" to be able quickly 'tQjlocate' the ample; it would'poss'ibly 'beof interest as a wireman to know precisely where;'in the vicinity of yy'he must" cut away concrete orsoil in 1 order to open 'pipe- 10; tap-a conduit vertically therefrom ipe 'itisironioutlet' l: at; and so ow deep I n m In general the apparatus comprises twq coact- 55 vanother.object qf ny invention; ;to prowide apparatus which-is, practical and'which pro- -lvidesgtor anadequately precise determination of the d nz h -le e-e. H

' tective ,casing flliwithinwhich there is mounted wiig sip ing'exploring-devices l5 and I8 one of which, 15, trav es; theinside of pipe [0, and the other of which, I8, is moved above the surface ,Il of the ground-v or pavement. ,So long as the two exploring devices l6 and llthave a certain relationship, a fixed electrical circuit condition is, maintained, affecting a signalling deviceor devices When that certain relationship ceases to exist,the circuit condition is also altered to change the signal 'lhe changing of the slgnaLissenSibIe to the operator so' othat he knows whe'ther or not \the' device l8 occupies the certain relationship QLtOZ-devicejJIB l' ,l r

,QThe'apparatus will now be described in greater detain The exploring device 16 comprises a proswitch. The casing 20 is connected to one end L of K flexible pushing rod, or tube, 22, sometimes .lknown aujffish.tube. Tube 22 is formed of flexible conduit well known in the electrical .wirhing, trades. ,The device IB is pushed into pipe 1031mm the utlet I2.

i 'ijhe j switchjwithin casing 20 connected in, and for, controlling a circuit for energizing signalling devices .24 and/or 26,- which devices 24 and 26 are above the ground and'visible oraudible toitheoperator. Theswitch within casing 20 is responsive to the presenceQand absence of device/IQ; inthefcertain relationship the switch maintains a fixed circuit condition; when that relationship ceases to exist, the fixed circuit con- !ditionalso ceases and'establishes another circuit condition. it b That certain relationship and those circuit conditions referred to above are determined, in the (preferred embodiment-of this invention,-.-by the particular constructions to be described. v

by The switch includes a housing 28 which isaluminllm. Dr 1 other nonmagnetiz able but, electrocondue'tive' 'metal.v l-Ious'irig 28 has two flattparallel, disc shaped walls ,30 and 32 joined by agenerally cylindrical wall ,portion, Mt- These wall portions form a sealed container having an axial opening through wall 32. -Within the container there is placed alglobule of v mercury 36, and the wall 3,4 is. preferably weighted by a small mass of metal alplaced on wall 34; Aswill. be made clear-,;the mass 38 always remainslowermost due mon axis of bearings 50 and 52 is perpendicular to and intersects the axis of bearings 44 and 46. This plural bearing support and structure insure that the side walls 30 and 32 of the switch 28 always remain in vertical planes parallel to the direction of gravitational force, under the influence of mass 38 or its equivalent, and that the axes of shafts 40 and 42 remain horizontal. The wall 34 of theswitch is provided with a' slight peripheral internal groove 56 to insure the posivane 18 is near or at vertical. This condition can exist when a strong unidirectional magnetic field is produced with its resultant axis of flux lying within angle 0. Device I8 effects this function by providing an electromagnet I the magnetic axis of which is vertical. Device I8 comprises a case I02 with a handle I04. A magnet core I06 is fixed in casing I02 so that when the tioning of the mercury globule 36 at a fixed location between the side walls 30 and 32. h

The frame 54 provides bearing brackets 58 secured to a. rigid ring 60 which is in turn suitably fastened to a bell section 62 of the casing 20. Bell section 62 is provided with a neck 64 which is fitted within fiexibletubing 22. A nose portion 66 of the casing 20 is suitably secured to, the ring 60 by means of a section of flexible tubingv 68 to provide a liquid sealed enclosure for the switch parts, and to, enablethe device I6 to more readily pass around bends and obstructions in the pipe I0- l The shaft 40 passes through wall 32 of the switch 28 andis electrically insulated therefrom by a grommet I0 of rubber secured in position by a gland nut I2 and a shoulder flange I4. The shaft 42 is of metal secured in any suitable manner to wall 30.

v A second flange I6 is provided on the end of shaft 40 within housing 28 to provide a shaft bearing for a movable contact arm I8. Arm I8 is formed of highly and permanently magnetized steel, constituting a magnetic vane having pointed tips80and .82. The magnetic vane 18 normally takes a position coinciding with the nearly horizontal earth magnetic field, the shaft 40 being always horizontal. .Thetips 80 and82 are equally distant from the shaft center c,

and extend so as to. only contact the globule of mercury through a vertical angle? as shown in Fig. 3. The depth :ry of the pipe is determinable because of. the existenceof the angle 6', as will be pointed out. j Current is conducted from a bat ry 84through an insulated conductor 86 extending through tube 22 into shell 20 where it is attached to a terminal 8B. Terminal 88 is mounted in insulation 90 of bracket 50and is extended to provide a stationary brush 92 co-axial with bearing 60. A second brush .94 carried by pivoted support '48 is in continuous axial contact withbrush82 and is electrically connected througha conductor 06 and a suitable brush 9'! to contact the end of shaft 40. Shaft 40 bears in insulating hearing 99, and the conductor 96, with brushes 94 and 91, are insulated as at 0| and 93. I Electrical signal devices 24 and 26 have their terminii connectedin circuit to the other terminal of battery 84 and to the tube 22'as at.98. The tube 22 is provided with a scale 23 by means of which the length of it within pipe I0 may be determined; j

When vane I8 contacts theglobuleof mercury a. circuit is completed from battery 84 through conductor 86, brushes 92 and 94, conductor 96, brush 01, shaft 40, vane I8 to the globule of mercury 36, thence through the walls of switch to shaft 42 and thence to support 48 from which it passes through bearings 52 and 54 to hell l9, then to and through the flexible tube 22 back to battery 84 through the signal devices 24 and 26. It will be clear that the switch 28 closesthis circuit only when the vane I8 'is in a position within the'limits of angle 6, that is,when the mg points a, b,-and c:

casing I04 is suspended by the hand, the field of magnet I00 is about vertical. Magnet I00 is either a permanent magnet, or a direct current excited magnet which produces north and south excited poles.

Assuming that the lower end of magnet I00 is a north pole, it will be understood that the south pole of vane I8 takes the top position when the magnet I00 is vertically above device I 0; or, more precisely stated, when the center of action of the pole N of magnet I00 lies within the angle 0 above the shaft center 0, the s pole of vane I8 also lies within angle 0.

of magnet I00 was stated to be determinable be- 'The distance from-a or b to the center c of shaft 40 is proportional to" the distance between a and b, or the length'ofthe line ab. The ratio of ab to ac is determined by a preliminary callbration where ac is known and ab is measured as the distance between two-points corresponding to a-ancl b at which the circuit makes and breaks when the magnet pole Nof magnet I00 is-mov ed horizontally in and out of angle 0.

I When thisratio is once determined, it is employed in the followingequation, in which 'a,-b'

and 0 represent new positions of the correspond- I. I I I I i I a 0 equals b 0 equals (at h Thus the depth of the pipeis measured with a. practical degree of accuracy. The position of point y, vertically above an, is, evidently, on the bisectorof angle 0, or at the midpoint of ab. In Fig. 3, e and I represent positions of magnet I00 at which the signal circuit is open. ..It is not essential that the contact 36 be of. mercury. It may be of solid metal fixed in switch casing; 28. ,When contact 36 is'made of solid metalit is clear that the vane 18 cannotpass the contact 36. It is-not necessary that it doso. It .will be noted that, by'simply reversing the position of poles S and N of magnet I00, the N pole or the S pole of vane I8 rotates through about degreesof angle'and. contacts 36 from the other side. Therefore the position of'the pole N of magnet I 00 on one side of the angle 0 and of pole s of magnet I00 on the other side of: angle 0 corresponding to the positions a and b or a. and b' at which the circuit makes and breaks, serves the same purpose of determining depth of c. below 1. Apparatus for determining the location of 1 a hidden pipe comprising in combination: a flexible rod, a switch secured to one end of said rod, a signalling device, and an electrical circuit ineluding said switch and signaling device, said circuit including conductors extending from the switch and along the rod to the signaling device; and a separate magnet for actuating the switch to control the circuit.

2. The method of determining the location of a pipe which includes extending a circuit controlling member into the pipe and actuating the controlling member from points outside the pipe.

CLAUDE EUGENE POPE.

No references cited.

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