US1986170A - Direction finder - Google Patents

Description

Jan. 1, 1935. c. w. WIEGAND DIRECTION FINDER l Filed' Dec. 5v, 1952 vatentecl- Jan. 19.35

' UNITED STATES This invention relates to novelj'improvements! in direction finders. l

One of the main objects of `this invention-is toy provide a direction finder .of a novel construction which renders it highly efcient andat the sainetirne inexpensive.

Another object is to provide a direction finder'.

having its rotary magnetic barl or 'pointerv so mounted that the center of the magnetic `,zone of one of its poles is placedlsubstantially on the axis of rotation `of the finder, 'wherebys'aid `zone and pole are irnpounded and rendered 'ineffective, while the other .polefalone isfree to functhis bar. can bequickly set to point'feithertoivard the north or toward thesouth, whichever may be deemed .preferable .at `.the time.. l.

These andV other objects and .advantages become :apparent from the followingide'scription, taken'inconnection with the accompanying.drawing, in which the invention isishownf-in--its;pre.`1

ferred forms, it beingfunderstood that various other arrangements and forms of construction may be resorted to for carrying out the objects and purposes of this invention.

In the drawing:

Fig. 1 is a plan view of my invention shown in one of its preferred forms of construction.

Fig. 2 is an enlarged vertical sectional view thereof, taken on line 2 2 of Fig. `1.

Fig. 3 is an enlarged vertical cross-sectional view, taken on line 3-3 of Fig. 2.

Fig. 4 is a plan View of the magnetized bar or needle used in this invention, the zones of magnetic influence of its poles being indicated.

Fig. 5 is an elevational View, partly broken away, showing my invention in a modified form, with the bar suspended by a thread.

In my invention, in either of its forms, the magnetic bar or needle is mounted so that one of its poles is confined While the other pole alone is free to function, unhampered by the confined pole, and thus enabling it to operate with increased efciency. The construction is so arranged that the needle may be readily reversed, and either pole may be confined leaving the opposite one or the selected pole alone free.

In the form shown in Figs. 1 to 4 of the drawing my novel direction finder comprises a magnetized bar or needle 10 of paramagnetic material which is provided with a positive pole 11 at one end and a negative pole 11' at the other. This b ar is provided with a perforation12 adjacent each end, and each ofthese perforations is placed substantially and vafs-n`early as possible at the center vof the `magneticlzone of influence of the pole, as indicatedr in Fig. 4b'y the broken curvedl 5 line 13 atfeach end of the bar.

The means for supporting 1the `bar or needle comprises a vsleeve or casing 14 having a flat sleeve portion 15 at one end for receiving either end Yof bar loslidably and removably therein.

Said sleeve has a cap 16 on its top containing a jewel 17 in Iits vupper end, 'which restsr rotatably on the top end of a spindle or spin-shaft '18 extendngfthrough one of the perforations 12 andthrough suitable openings providedvin' the sleeve.

Means for balancing magnetic bar 10 comprises a' :bar orV arm'21 4which has one end `mounted ina sleeve portion 22 on sleeve 14, opposite sleeve portion15, so that saidbars 10 and 2'1 are substantially alined longitudinally. This arm consists of ai non-'magnetic material, such as bakelite, compressed rubber, aluminum, or some other suitable non-magneticjmaterial. A

,Toprovidefor avery accurate balancing of the arm 21 and bar 10 on shaft 18, a weight or band 23 is preferably mounted on arm 21, so as to be slidably adjustable thereon.

In this form a housing or casing 25 is provided for supporting and -protecting the finder. 30 Spin-shaft 18 is mounted in the center of its base member 26, and a crystal or transparent cover 27 is mounted at the top of the casing, for example as indicated in the drawing.

This magnetic bar 10 is preferably also pro- 35 vided with a perforation 28 at its middle or neutral section, besides perforations 12 of the poles, so that spindle 18 can be passed` through said perforation 28 and the bar can be mounted centrally in sleeve 14, while arm 21 and weight 23 40 are omitted; and as said sleeve is constructed so as to balance on spindle 18, this device is also adapted to be operated like the usual compass needle.

As the bar or needle 10 is removably and interchangeably mountable with either of its ends in sleeve portion 15, and as the perforation 12 of the confined pole, wherethrough shaft 18 eX`- tends, is positioned substantially centrally of its magnetic yzone of influence, said pole with its 50 magnetic zone will be confined, thereby leaving the other pole alone free to function, unhampered by said confined pole `and with increased eiliciency. With this reversibility the bar can be readilymounted so that either its north-seeking pole or its south-seeking pole is placed free to operate, whichever may be deemed most expedient at the time.

In Fig. 5 of the drawing my invention is illustrated ina modified form. The magnetized bar therein is interchangeably mountable with either of its endsin the portion of the sleeve member 14', in the same manner as in the preceding form, and the balancing arm 2l has one end mounted in the portion 22 of said-sleeve, while a weight 23' is adjustablymounted on said arm. Y Y

In this form a yoke or eye member is provided on top of sleeve 14', Whereto a cord o r thread 31 is attached which is preferably in the` form of a silk thread, the same being suspended from the top of a transparent cupola" or dome 32 provided with a suitable base '33. v'Said thread. is readily secured in a suitable opening provided element 34 or the like; c In this fornir of my invention I have found that the bar and arm oscillate freely on the thread and that `said thread remains perfectly vertical and constitutes a perfect axis of rotation, in the nature of a perfect plumb bob', Without any deviations or swinging in circles, as isv generally the case with the usual plumb bobs.

in the top of said dome, by means of a wedge I have illustrated two of the several vforms of' positive pole at lone end and a negative pole at the other end, a balancing arm extending beyondone end of said bar and substantially alined therewith, a sleeve containing apair of sockets,

one for removably receiving one end of said army and the other for interchangeably receiving either end of said bar so as to have either pole readily and interchangeably connected with said arm while the other pole is free, means rotatably supporting said sleeve for pivotal movement about a vertical axis, and means adjustable on said arm for accurately balancing it and the bar to rotate in a horizontal plane, the axis of rotation of the nder extending substantially through the center of the magnetic zone of the pivoted pole thereby impounding it and leaving the other pole free torotate about the pivoted pole.

2. A direction finder consisting of a straight bar of magnetized metal having a positive pole at Qneend and a negative pole at the other, there being' va^perforation provided in the center of the ,magneticzone of each pole adjacent each end have either, end of the `bar interchangeably mounted therein, and pivoting means including acap mounted on said sleeve and a pivot pin extending .through the perforation in the pole intosaidA cap,thereby supporting the bar and arm to rotate on an axis extending through the center ofwthe magnetic zone of the connected poleto-.impound the same and leave the other pole free torotate thereabout.

3. A direction nder consisting of a magthread suspended centrallytherein which has its lower end connected tosaid sleeve, whereby the barand arm are rotatablysupported so that the axis of rotation passes through the center of the magnetic zone of the bars attached pole'while itsother .pole is yfree to rotate thereabout.

Y f CRIS W. WIEGAND.

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